diff --git a/examples/custom.rs b/examples/custom.rs
index 7b41e97..a708afb 100644
--- a/examples/custom.rs
+++ b/examples/custom.rs
@@ -42,7 +42,7 @@ impl HtmlHandler<MyError> for MyHtmlHandler {
                         w,
                         "<h{0}><a id=\"{1}\" href=\"#{1}\">",
                         title.level,
-                        slugify!(title.raw),
+                        slugify!(&title.raw),
                     )?;
                 }
             }
diff --git a/examples/syntect.rs b/examples/syntect.rs
index 9e61772..b9eda56 100644
--- a/examples/syntect.rs
+++ b/examples/syntect.rs
@@ -46,7 +46,7 @@ impl HtmlHandler<Error> for SyntectHtmlHandler {
             Element::InlineSrc(inline_src) => write!(
                 w,
                 "<code>{}</code>",
-                self.highlight(Some(inline_src.lang), inline_src.body)
+                self.highlight(Some(&inline_src.lang), &inline_src.body)
             )?,
             Element::SourceBlock(block) => {
                 if block.language.is_empty() {
@@ -56,7 +56,7 @@ impl HtmlHandler<Error> for SyntectHtmlHandler {
                         w,
                         "<div class=\"org-src-container\"><pre class=\"src src-{}\">{}</pre></div>",
                         block.language,
-                        self.highlight(Some(block.language), block.contents)
+                        self.highlight(Some(&block.language), &block.contents)
                     )?
                 }
             }
@@ -68,7 +68,7 @@ impl HtmlHandler<Error> for SyntectHtmlHandler {
             Element::ExampleBlock(block) => write!(
                 w,
                 "<pre class=\"example\">{}</pre>",
-                self.highlight(None, block.contents)
+                self.highlight(None, &block.contents)
             )?,
             _ => self.default_hanlder.start(w, element)?,
         }
diff --git a/src/elements/block.rs b/src/elements/block.rs
index 8bcec09..83bb027 100644
--- a/src/elements/block.rs
+++ b/src/elements/block.rs
@@ -1,3 +1,5 @@
+use std::borrow::Cow;
+
 use nom::{bytes::complete::tag_no_case, character::complete::alpha1, sequence::preceded, IResult};
 
 use crate::parsers::{take_lines_till, take_until_eol};
@@ -5,8 +7,8 @@ use crate::parsers::{take_lines_till, take_until_eol};
 #[cfg_attr(test, derive(PartialEq))]
 #[derive(Debug)]
 pub struct Block<'a> {
-    pub name: &'a str,
-    pub args: Option<&'a str>,
+    pub name: Cow<'a, str>,
+    pub args: Option<Cow<'a, str>>,
 }
 
 impl Block<'_> {
@@ -22,8 +24,12 @@ impl Block<'_> {
             input,
             (
                 Block {
-                    name,
-                    args: if args.is_empty() { None } else { Some(args) },
+                    name: name.into(),
+                    args: if args.is_empty() {
+                        None
+                    } else {
+                        Some(args.into())
+                    },
                 },
                 contents,
             ),
@@ -39,7 +45,7 @@ fn parse() {
             "",
             (
                 Block {
-                    name: "SRC",
+                    name: "SRC".into(),
                     args: None,
                 },
                 ""
@@ -52,8 +58,8 @@ fn parse() {
             "",
             (
                 Block {
-                    name: "SRC",
-                    args: Some("javascript"),
+                    name: "SRC".into(),
+                    args: Some("javascript".into()),
                 },
                 "console.log('Hello World!');\n"
             )
@@ -66,60 +72,60 @@ fn parse() {
 #[cfg_attr(test, derive(PartialEq))]
 #[cfg_attr(feature = "ser", derive(serde::Serialize))]
 pub struct SpecialBlock<'a> {
-    pub parameters: Option<&'a str>,
-    pub name: &'a str,
+    pub parameters: Option<Cow<'a, str>>,
+    pub name: Cow<'a, str>,
 }
 
 #[derive(Debug)]
 #[cfg_attr(test, derive(PartialEq))]
 #[cfg_attr(feature = "ser", derive(serde::Serialize))]
 pub struct QuoteBlock<'a> {
-    pub parameters: Option<&'a str>,
+    pub parameters: Option<Cow<'a, str>>,
 }
 
 #[derive(Debug)]
 #[cfg_attr(test, derive(PartialEq))]
 #[cfg_attr(feature = "ser", derive(serde::Serialize))]
 pub struct CenterBlock<'a> {
-    pub parameters: Option<&'a str>,
+    pub parameters: Option<Cow<'a, str>>,
 }
 
 #[derive(Debug)]
 #[cfg_attr(test, derive(PartialEq))]
 #[cfg_attr(feature = "ser", derive(serde::Serialize))]
 pub struct VerseBlock<'a> {
-    pub parameters: Option<&'a str>,
+    pub parameters: Option<Cow<'a, str>>,
 }
 
 #[derive(Debug)]
 #[cfg_attr(test, derive(PartialEq))]
 #[cfg_attr(feature = "ser", derive(serde::Serialize))]
 pub struct CommentBlock<'a> {
-    pub data: Option<&'a str>,
-    pub contents: &'a str,
+    pub data: Option<Cow<'a, str>>,
+    pub contents: Cow<'a, str>,
 }
 
 #[derive(Debug)]
 #[cfg_attr(test, derive(PartialEq))]
 #[cfg_attr(feature = "ser", derive(serde::Serialize))]
 pub struct ExampleBlock<'a> {
-    pub data: Option<&'a str>,
-    pub contents: &'a str,
+    pub data: Option<Cow<'a, str>>,
+    pub contents: Cow<'a, str>,
 }
 
 #[derive(Debug)]
 #[cfg_attr(test, derive(PartialEq))]
 #[cfg_attr(feature = "ser", derive(serde::Serialize))]
 pub struct ExportBlock<'a> {
-    pub data: &'a str,
-    pub contents: &'a str,
+    pub data: Cow<'a, str>,
+    pub contents: Cow<'a, str>,
 }
 
 #[derive(Debug)]
 #[cfg_attr(test, derive(PartialEq))]
 #[cfg_attr(feature = "ser", derive(serde::Serialize))]
 pub struct SourceBlock<'a> {
-    pub contents: &'a str,
-    pub language: &'a str,
-    pub arguments: &'a str,
+    pub contents: Cow<'a, str>,
+    pub language: Cow<'a, str>,
+    pub arguments: Cow<'a, str>,
 }
diff --git a/src/elements/clock.rs b/src/elements/clock.rs
index 7fbbaab..c764823 100644
--- a/src/elements/clock.rs
+++ b/src/elements/clock.rs
@@ -1,7 +1,9 @@
+use std::borrow::Cow;
+
 use nom::{
     bytes::complete::tag,
     character::complete::{char, digit1, space0},
-    combinator::{peek, recognize},
+    combinator::recognize,
     sequence::separated_pair,
     IResult,
 };
@@ -22,18 +24,18 @@ pub enum Clock<'a> {
         start: Datetime<'a>,
         end: Datetime<'a>,
         #[cfg_attr(feature = "ser", serde(skip_serializing_if = "Option::is_none"))]
-        repeater: Option<&'a str>,
+        repeater: Option<Cow<'a, str>>,
         #[cfg_attr(feature = "ser", serde(skip_serializing_if = "Option::is_none"))]
-        delay: Option<&'a str>,
-        duration: &'a str,
+        delay: Option<Cow<'a, str>>,
+        duration: Cow<'a, str>,
     },
     /// running Clock
     Running {
         start: Datetime<'a>,
         #[cfg_attr(feature = "ser", serde(skip_serializing_if = "Option::is_none"))]
-        repeater: Option<&'a str>,
+        repeater: Option<Cow<'a, str>>,
         #[cfg_attr(feature = "ser", serde(skip_serializing_if = "Option::is_none"))]
-        delay: Option<&'a str>,
+        delay: Option<Cow<'a, str>>,
     },
 }
 
@@ -41,7 +43,6 @@ impl Clock<'_> {
     pub(crate) fn parse(input: &str) -> IResult<&str, Element<'_>> {
         let (input, _) = tag("CLOCK:")(input)?;
         let (input, _) = space0(input)?;
-        let (input, _) = peek(tag("["))(input)?;
         let (input, timestamp) = Timestamp::parse_inactive(input)?;
 
         match timestamp {
@@ -64,7 +65,7 @@ impl Clock<'_> {
                         end,
                         repeater,
                         delay,
-                        duration,
+                        duration: duration.into(),
                     }),
                 ))
             }
@@ -83,7 +84,9 @@ impl Clock<'_> {
                     }),
                 ))
             }
-            _ => unreachable!(),
+            _ => unreachable!(
+                "`Timestamp::parse_inactive` only returns `Timestamp::InactiveRange` or `Timestamp::Inactive`."
+            ),
         }
     }
 
@@ -150,7 +153,7 @@ fn parse() {
                     year: 2003,
                     month: 9,
                     day: 16,
-                    dayname: "Tue",
+                    dayname: "Tue".into(),
                     hour: Some(9),
                     minute: Some(39)
                 },
@@ -168,7 +171,7 @@ fn parse() {
                     year: 2003,
                     month: 9,
                     day: 16,
-                    dayname: "Tue",
+                    dayname: "Tue".into(),
                     hour: Some(9),
                     minute: Some(39)
                 },
@@ -176,13 +179,13 @@ fn parse() {
                     year: 2003,
                     month: 9,
                     day: 16,
-                    dayname: "Tue",
+                    dayname: "Tue".into(),
                     hour: Some(10),
                     minute: Some(39)
                 },
                 repeater: None,
                 delay: None,
-                duration: "1:00",
+                duration: "1:00".into(),
             })
         ))
     );
diff --git a/src/elements/cookie.rs b/src/elements/cookie.rs
index f02607b..7dcea8a 100644
--- a/src/elements/cookie.rs
+++ b/src/elements/cookie.rs
@@ -1,3 +1,5 @@
+use std::borrow::Cow;
+
 use nom::{
     branch::alt,
     bytes::complete::tag,
@@ -11,7 +13,7 @@ use nom::{
 #[cfg_attr(feature = "ser", derive(serde::Serialize))]
 #[derive(Debug)]
 pub struct Cookie<'a> {
-    pub value: &'a str,
+    pub value: Cow<'a, str>,
 }
 
 impl Cookie<'_> {
@@ -26,7 +28,12 @@ impl Cookie<'_> {
             tag("]"),
         ))(input)?;
 
-        Ok((input, Cookie { value }))
+        Ok((
+            input,
+            Cookie {
+                value: value.into(),
+            },
+        ))
     }
 }
 
@@ -34,22 +41,66 @@ impl Cookie<'_> {
 fn parse() {
     assert_eq!(
         Cookie::parse("[1/10]"),
-        Ok(("", Cookie { value: "[1/10]" }))
+        Ok((
+            "",
+            Cookie {
+                value: "[1/10]".into()
+            }
+        ))
     );
     assert_eq!(
         Cookie::parse("[1/1000]"),
-        Ok(("", Cookie { value: "[1/1000]" }))
+        Ok((
+            "",
+            Cookie {
+                value: "[1/1000]".into()
+            }
+        ))
+    );
+    assert_eq!(
+        Cookie::parse("[10%]"),
+        Ok((
+            "",
+            Cookie {
+                value: "[10%]".into()
+            }
+        ))
+    );
+    assert_eq!(
+        Cookie::parse("[%]"),
+        Ok((
+            "",
+            Cookie {
+                value: "[%]".into()
+            }
+        ))
+    );
+    assert_eq!(
+        Cookie::parse("[/]"),
+        Ok((
+            "",
+            Cookie {
+                value: "[/]".into()
+            }
+        ))
     );
-    assert_eq!(Cookie::parse("[10%]"), Ok(("", Cookie { value: "[10%]" })));
-    assert_eq!(Cookie::parse("[%]"), Ok(("", Cookie { value: "[%]" })));
-    assert_eq!(Cookie::parse("[/]"), Ok(("", Cookie { value: "[/]" })));
     assert_eq!(
         Cookie::parse("[100/]"),
-        Ok(("", Cookie { value: "[100/]" }))
+        Ok((
+            "",
+            Cookie {
+                value: "[100/]".into()
+            }
+        ))
     );
     assert_eq!(
         Cookie::parse("[/100]"),
-        Ok(("", Cookie { value: "[/100]" }))
+        Ok((
+            "",
+            Cookie {
+                value: "[/100]".into()
+            }
+        ))
     );
 
     assert!(Cookie::parse("[10% ]").is_err());
diff --git a/src/elements/drawer.rs b/src/elements/drawer.rs
index cc764e3..516107d 100644
--- a/src/elements/drawer.rs
+++ b/src/elements/drawer.rs
@@ -1,3 +1,5 @@
+use std::borrow::Cow;
+
 use crate::parsers::{eol, take_lines_till};
 
 use nom::{
@@ -10,7 +12,7 @@ use nom::{
 #[cfg_attr(feature = "ser", derive(serde::Serialize))]
 #[derive(Debug)]
 pub struct Drawer<'a> {
-    pub name: &'a str,
+    pub name: Cow<'a, str>,
 }
 
 impl Drawer<'_> {
@@ -24,7 +26,7 @@ impl Drawer<'_> {
         let (input, _) = eol(input)?;
         let (input, contents) = take_lines_till(|line| line.eq_ignore_ascii_case(":END:"))(input)?;
 
-        Ok((input, (Drawer { name }, contents)))
+        Ok((input, (Drawer { name: name.into() }, contents)))
     }
 }
 
@@ -32,6 +34,14 @@ impl Drawer<'_> {
 fn parse() {
     assert_eq!(
         Drawer::parse(":PROPERTIES:\n  :CUSTOM_ID: id\n  :END:"),
-        Ok(("", (Drawer { name: "PROPERTIES" }, "  :CUSTOM_ID: id\n")))
+        Ok((
+            "",
+            (
+                Drawer {
+                    name: "PROPERTIES".into()
+                },
+                "  :CUSTOM_ID: id\n"
+            )
+        ))
     )
 }
diff --git a/src/elements/dyn_block.rs b/src/elements/dyn_block.rs
index 65c2744..9da0519 100644
--- a/src/elements/dyn_block.rs
+++ b/src/elements/dyn_block.rs
@@ -1,3 +1,5 @@
+use std::borrow::Cow;
+
 use crate::elements::Element;
 use crate::parsers::{take_lines_till, take_until_eol};
 
@@ -11,9 +13,9 @@ use nom::{
 #[cfg_attr(feature = "ser", derive(serde::Serialize))]
 #[derive(Debug)]
 pub struct DynBlock<'a> {
-    pub block_name: &'a str,
+    pub block_name: Cow<'a, str>,
     #[cfg_attr(feature = "ser", serde(skip_serializing_if = "Option::is_none"))]
-    pub arguments: Option<&'a str>,
+    pub arguments: Option<Cow<'a, str>>,
 }
 
 impl DynBlock<'_> {
@@ -30,8 +32,12 @@ impl DynBlock<'_> {
             input,
             (
                 Element::DynBlock(DynBlock {
-                    block_name: name,
-                    arguments: if args.is_empty() { None } else { Some(args) },
+                    block_name: name.into(),
+                    arguments: if args.is_empty() {
+                        None
+                    } else {
+                        Some(args.into())
+                    },
                 }),
                 contents,
             ),
@@ -48,8 +54,8 @@ fn parse() {
             "",
             (
                 Element::DynBlock(DynBlock {
-                    block_name: "clocktable",
-                    arguments: Some(":scope file"),
+                    block_name: "clocktable".into(),
+                    arguments: Some(":scope file".into()),
                 }),
                 "CONTENTS\n"
             )
diff --git a/src/elements/fn_def.rs b/src/elements/fn_def.rs
index a5e03c3..ca4efbe 100644
--- a/src/elements/fn_def.rs
+++ b/src/elements/fn_def.rs
@@ -1,3 +1,5 @@
+use std::borrow::Cow;
+
 use memchr::memchr;
 use nom::{
     bytes::complete::{tag, take_while1},
@@ -9,7 +11,7 @@ use nom::{
 #[cfg_attr(feature = "ser", derive(serde::Serialize))]
 #[derive(Debug)]
 pub struct FnDef<'a> {
-    pub label: &'a str,
+    pub label: Cow<'a, str>,
 }
 
 fn parse_label(input: &str) -> IResult<&str, &str> {
@@ -29,7 +31,13 @@ impl FnDef<'_> {
 
         let end = memchr(b'\n', tail.as_bytes()).unwrap_or_else(|| tail.len());
 
-        Some((&tail[end..], FnDef { label }, &tail[0..end]))
+        Some((
+            &tail[end..],
+            FnDef {
+                label: label.into(),
+            },
+            &tail[0..end],
+        ))
     }
 }
 
@@ -37,19 +45,37 @@ impl FnDef<'_> {
 fn parse() {
     assert_eq!(
         FnDef::parse("[fn:1] https://orgmode.org"),
-        Some(("", FnDef { label: "1" }, " https://orgmode.org"))
+        Some(("", FnDef { label: "1".into() }, " https://orgmode.org"))
     );
     assert_eq!(
         FnDef::parse("[fn:word_1] https://orgmode.org"),
-        Some(("", FnDef { label: "word_1" }, " https://orgmode.org"))
+        Some((
+            "",
+            FnDef {
+                label: "word_1".into()
+            },
+            " https://orgmode.org"
+        ))
     );
     assert_eq!(
         FnDef::parse("[fn:WORD-1] https://orgmode.org"),
-        Some(("", FnDef { label: "WORD-1" }, " https://orgmode.org"))
+        Some((
+            "",
+            FnDef {
+                label: "WORD-1".into()
+            },
+            " https://orgmode.org"
+        ))
     );
     assert_eq!(
         FnDef::parse("[fn:WORD]"),
-        Some(("", FnDef { label: "WORD" }, ""))
+        Some((
+            "",
+            FnDef {
+                label: "WORD".into()
+            },
+            ""
+        ))
     );
     assert_eq!(FnDef::parse("[fn:] https://orgmode.org"), None);
     assert_eq!(FnDef::parse("[fn:wor d] https://orgmode.org"), None);
diff --git a/src/elements/fn_ref.rs b/src/elements/fn_ref.rs
index eb6e2db..e1c0d98 100644
--- a/src/elements/fn_ref.rs
+++ b/src/elements/fn_ref.rs
@@ -1,3 +1,5 @@
+use std::borrow::Cow;
+
 use memchr::memchr2_iter;
 use nom::{
     bytes::complete::{tag, take_while},
@@ -12,9 +14,9 @@ use nom::{
 #[cfg_attr(feature = "ser", derive(serde::Serialize))]
 #[derive(Debug)]
 pub struct FnRef<'a> {
-    pub label: &'a str,
+    pub label: Cow<'a, str>,
     #[cfg_attr(feature = "ser", serde(skip_serializing_if = "Option::is_none"))]
-    pub definition: Option<&'a str>,
+    pub definition: Option<Cow<'a, str>>,
 }
 
 fn balanced_brackets(input: &str) -> IResult<&str, &str> {
@@ -40,7 +42,13 @@ impl FnRef<'_> {
         let (input, definition) = opt(preceded(tag(":"), balanced_brackets))(input)?;
         let (input, _) = tag("]")(input)?;
 
-        Ok((input, FnRef { label, definition }))
+        Ok((
+            input,
+            FnRef {
+                label: label.into(),
+                definition: definition.map(Into::into),
+            },
+        ))
     }
 }
 
@@ -51,7 +59,7 @@ fn parse() {
         Ok((
             "",
             FnRef {
-                label: "1",
+                label: "1".into(),
                 definition: None
             },
         ))
@@ -61,8 +69,8 @@ fn parse() {
         Ok((
             "",
             FnRef {
-                label: "1",
-                definition: Some("2")
+                label: "1".into(),
+                definition: Some("2".into())
             },
         ))
     );
@@ -71,8 +79,8 @@ fn parse() {
         Ok((
             "",
             FnRef {
-                label: "",
-                definition: Some("2")
+                label: "".into(),
+                definition: Some("2".into())
             },
         ))
     );
@@ -81,8 +89,8 @@ fn parse() {
         Ok((
             "",
             FnRef {
-                label: "",
-                definition: Some("[]")
+                label: "".into(),
+                definition: Some("[]".into())
             },
         ))
     );
diff --git a/src/elements/inline_call.rs b/src/elements/inline_call.rs
index fc51ee6..9b2edf9 100644
--- a/src/elements/inline_call.rs
+++ b/src/elements/inline_call.rs
@@ -1,3 +1,5 @@
+use std::borrow::Cow;
+
 use nom::{
     bytes::complete::{tag, take_till},
     combinator::opt,
@@ -11,12 +13,12 @@ use crate::elements::Element;
 #[cfg_attr(feature = "ser", derive(serde::Serialize))]
 #[derive(Debug)]
 pub struct InlineCall<'a> {
-    pub name: &'a str,
+    pub name: Cow<'a, str>,
     #[cfg_attr(feature = "ser", serde(skip_serializing_if = "Option::is_none"))]
-    pub inside_header: Option<&'a str>,
-    pub arguments: &'a str,
+    pub inside_header: Option<Cow<'a, str>>,
+    pub arguments: Cow<'a, str>,
     #[cfg_attr(feature = "ser", serde(skip_serializing_if = "Option::is_none"))]
-    pub end_header: Option<&'a str>,
+    pub end_header: Option<Cow<'a, str>>,
 }
 
 impl<'a> InlineCall<'a> {
@@ -42,10 +44,10 @@ impl<'a> InlineCall<'a> {
         Ok((
             input,
             Element::InlineCall(InlineCall {
-                name,
-                arguments,
-                inside_header,
-                end_header,
+                name: name.into(),
+                arguments: arguments.into(),
+                inside_header: inside_header.map(Into::into),
+                end_header: end_header.map(Into::into),
             }),
         ))
     }
@@ -58,8 +60,8 @@ fn parse() {
         Ok((
             "",
             Element::InlineCall(InlineCall {
-                name: "square",
-                arguments: "4",
+                name: "square".into(),
+                arguments: "4".into(),
                 inside_header: None,
                 end_header: None,
             }),
@@ -70,9 +72,9 @@ fn parse() {
         Ok((
             "",
             Element::InlineCall(InlineCall {
-                name: "square",
-                arguments: "4",
-                inside_header: Some(":results output"),
+                name: "square".into(),
+                arguments: "4".into(),
+                inside_header: Some(":results output".into()),
                 end_header: None,
             }),
         ))
@@ -82,10 +84,10 @@ fn parse() {
         Ok((
             "",
             Element::InlineCall(InlineCall {
-                name: "square",
-                arguments: "4",
+                name: "square".into(),
+                arguments: "4".into(),
                 inside_header: None,
-                end_header: Some(":results html"),
+                end_header: Some(":results html".into()),
             }),
         ))
     );
@@ -94,10 +96,10 @@ fn parse() {
         Ok((
             "",
             Element::InlineCall(InlineCall {
-                name: "square",
-                arguments: "4",
-                inside_header: Some(":results output"),
-                end_header: Some(":results html"),
+                name: "square".into(),
+                arguments: "4".into(),
+                inside_header: Some(":results output".into()),
+                end_header: Some(":results html".into()),
             }),
         ))
     );
diff --git a/src/elements/inline_src.rs b/src/elements/inline_src.rs
index 046df20..ebac5ab 100644
--- a/src/elements/inline_src.rs
+++ b/src/elements/inline_src.rs
@@ -1,3 +1,5 @@
+use std::borrow::Cow;
+
 use nom::{
     bytes::complete::{tag, take_till, take_while1},
     combinator::opt,
@@ -11,10 +13,10 @@ use crate::elements::Element;
 #[cfg_attr(feature = "ser", derive(serde::Serialize))]
 #[derive(Debug)]
 pub struct InlineSrc<'a> {
-    pub lang: &'a str,
+    pub lang: Cow<'a, str>,
     #[cfg_attr(feature = "ser", serde(skip_serializing_if = "Option::is_none"))]
-    pub options: Option<&'a str>,
-    pub body: &'a str,
+    pub options: Option<Cow<'a, str>>,
+    pub body: Cow<'a, str>,
 }
 
 impl InlineSrc<'_> {
@@ -34,9 +36,9 @@ impl InlineSrc<'_> {
         Ok((
             input,
             Element::InlineSrc(InlineSrc {
-                lang,
-                options,
-                body,
+                lang: lang.into(),
+                options: options.map(Into::into),
+                body: body.into(),
             }),
         ))
     }
@@ -49,9 +51,9 @@ fn parse() {
         Ok((
             "",
             Element::InlineSrc(InlineSrc {
-                lang: "C",
+                lang: "C".into(),
                 options: None,
-                body: "int a = 0;"
+                body: "int a = 0;".into()
             }),
         ))
     );
@@ -60,9 +62,9 @@ fn parse() {
         Ok((
             "",
             Element::InlineSrc(InlineSrc {
-                lang: "xml",
-                options: Some(":exports code"),
-                body: "<tag>text</tag>",
+                lang: "xml".into(),
+                options: Some(":exports code".into()),
+                body: "<tag>text</tag>".into(),
             }),
         ))
     );
diff --git a/src/elements/keyword.rs b/src/elements/keyword.rs
index 810d603..747f0fd 100644
--- a/src/elements/keyword.rs
+++ b/src/elements/keyword.rs
@@ -1,3 +1,5 @@
+use std::borrow::Cow;
+
 use nom::{
     bytes::complete::{tag, take_till},
     combinator::opt,
@@ -12,17 +14,17 @@ use crate::parsers::take_until_eol;
 #[cfg_attr(feature = "ser", derive(serde::Serialize))]
 #[derive(Debug)]
 pub struct Keyword<'a> {
-    pub key: &'a str,
+    pub key: Cow<'a, str>,
     #[cfg_attr(feature = "ser", serde(skip_serializing_if = "Option::is_none"))]
-    pub optional: Option<&'a str>,
-    pub value: &'a str,
+    pub optional: Option<Cow<'a, str>>,
+    pub value: Cow<'a, str>,
 }
 
 #[cfg_attr(test, derive(PartialEq))]
 #[cfg_attr(feature = "ser", derive(serde::Serialize))]
 #[derive(Debug)]
 pub struct BabelCall<'a> {
-    pub value: &'a str,
+    pub value: Cow<'a, str>,
 }
 
 impl Keyword<'_> {
@@ -40,14 +42,19 @@ impl Keyword<'_> {
         let (input, value) = take_until_eol(input)?;
 
         if key.eq_ignore_ascii_case("CALL") {
-            Ok((input, Element::BabelCall(BabelCall { value })))
+            Ok((
+                input,
+                Element::BabelCall(BabelCall {
+                    value: value.into(),
+                }),
+            ))
         } else {
             Ok((
                 input,
                 Element::Keyword(Keyword {
-                    key,
-                    optional,
-                    value,
+                    key: key.into(),
+                    optional: optional.map(Into::into),
+                    value: value.into(),
                 }),
             ))
         }
@@ -61,9 +68,9 @@ fn parse() {
         Ok((
             "",
             Element::Keyword(Keyword {
-                key: "KEY",
+                key: "KEY".into(),
                 optional: None,
-                value: "",
+                value: "".into(),
             })
         ))
     );
@@ -72,9 +79,9 @@ fn parse() {
         Ok((
             "",
             Element::Keyword(Keyword {
-                key: "KEY",
+                key: "KEY".into(),
                 optional: None,
-                value: "VALUE",
+                value: "VALUE".into(),
             })
         ))
     );
@@ -83,9 +90,9 @@ fn parse() {
         Ok((
             "",
             Element::Keyword(Keyword {
-                key: "K_E_Y",
+                key: "K_E_Y".into(),
                 optional: None,
-                value: "VALUE",
+                value: "VALUE".into(),
             })
         ))
     );
@@ -94,9 +101,9 @@ fn parse() {
         Ok((
             "",
             Element::Keyword(Keyword {
-                key: "KEY",
+                key: "KEY".into(),
                 optional: None,
-                value: "VALUE",
+                value: "VALUE".into(),
             })
         ))
     );
@@ -108,9 +115,9 @@ fn parse() {
         Ok((
             "",
             Element::Keyword(Keyword {
-                key: "RESULTS",
+                key: "RESULTS".into(),
                 optional: None,
-                value: "",
+                value: "".into(),
             })
         ))
     );
@@ -120,9 +127,9 @@ fn parse() {
         Ok((
             "",
             Element::Keyword(Keyword {
-                key: "ATTR_LATEX",
+                key: "ATTR_LATEX".into(),
                 optional: None,
-                value: ":width 5cm",
+                value: ":width 5cm".into(),
             })
         ))
     );
@@ -132,7 +139,7 @@ fn parse() {
         Ok((
             "",
             Element::BabelCall(BabelCall {
-                value: "double(n=4)",
+                value: "double(n=4)".into(),
             })
         ))
     );
@@ -142,9 +149,9 @@ fn parse() {
         Ok((
             "",
             Element::Keyword(Keyword {
-                key: "CAPTION",
-                optional: Some("Short caption"),
-                value: "Longer caption.",
+                key: "CAPTION".into(),
+                optional: Some("Short caption".into()),
+                value: "Longer caption.".into(),
             })
         ))
     );
diff --git a/src/elements/link.rs b/src/elements/link.rs
index d202ed6..15e7af1 100644
--- a/src/elements/link.rs
+++ b/src/elements/link.rs
@@ -1,3 +1,5 @@
+use std::borrow::Cow;
+
 use nom::{
     bytes::complete::{tag, take_while},
     combinator::opt,
@@ -11,9 +13,9 @@ use crate::elements::Element;
 #[cfg_attr(feature = "ser", derive(serde::Serialize))]
 #[derive(Debug)]
 pub struct Link<'a> {
-    pub path: &'a str,
+    pub path: Cow<'a, str>,
     #[cfg_attr(feature = "ser", serde(skip_serializing_if = "Option::is_none"))]
-    pub desc: Option<&'a str>,
+    pub desc: Option<Cow<'a, str>>,
 }
 
 impl Link<'_> {
@@ -30,7 +32,13 @@ impl Link<'_> {
             tag("]"),
         ))(input)?;
         let (input, _) = tag("]")(input)?;
-        Ok((input, Element::Link(Link { path, desc })))
+        Ok((
+            input,
+            Element::Link(Link {
+                path: path.into(),
+                desc: desc.map(Into::into),
+            }),
+        ))
     }
 }
 
@@ -41,7 +49,7 @@ fn parse() {
         Ok((
             "",
             Element::Link(Link {
-                path: "#id",
+                path: "#id".into(),
                 desc: None
             },)
         ))
@@ -51,8 +59,8 @@ fn parse() {
         Ok((
             "",
             Element::Link(Link {
-                path: "#id",
-                desc: Some("desc")
+                path: "#id".into(),
+                desc: Some("desc".into())
             })
         ))
     );
diff --git a/src/elements/list.rs b/src/elements/list.rs
index d945656..cb20541 100644
--- a/src/elements/list.rs
+++ b/src/elements/list.rs
@@ -1,3 +1,5 @@
+use std::borrow::Cow;
+
 use memchr::memchr_iter;
 use std::iter::once;
 
@@ -65,7 +67,7 @@ impl List {
 #[cfg_attr(feature = "ser", derive(serde::Serialize))]
 #[derive(Debug)]
 pub struct ListItem<'a> {
-    pub bullet: &'a str,
+    pub bullet: Cow<'a, str>,
 }
 
 impl ListItem<'_> {
@@ -87,7 +89,7 @@ impl ListItem<'_> {
                     return (
                         &text[pos..],
                         ListItem {
-                            bullet: &text[indent..off],
+                            bullet: text[indent..off].into(),
                         },
                         &text[off..pos],
                     );
@@ -99,7 +101,7 @@ impl ListItem<'_> {
         (
             "",
             ListItem {
-                bullet: &text[indent..off],
+                bullet: text[indent..off].into(),
             },
             &text[off..],
         )
diff --git a/src/elements/macros.rs b/src/elements/macros.rs
index 7830ce6..5caab9f 100644
--- a/src/elements/macros.rs
+++ b/src/elements/macros.rs
@@ -1,3 +1,5 @@
+use std::borrow::Cow;
+
 use nom::{
     bytes::complete::{tag, take, take_until, take_while1},
     combinator::{opt, verify},
@@ -11,9 +13,9 @@ use crate::elements::Element;
 #[cfg_attr(feature = "ser", derive(serde::Serialize))]
 #[derive(Debug)]
 pub struct Macros<'a> {
-    pub name: &'a str,
+    pub name: Cow<'a, str>,
     #[cfg_attr(feature = "ser", serde(skip_serializing_if = "Option::is_none"))]
-    pub arguments: Option<&'a str>,
+    pub arguments: Option<Cow<'a, str>>,
 }
 
 impl Macros<'_> {
@@ -27,7 +29,13 @@ impl Macros<'_> {
         let (input, arguments) = opt(delimited(tag("("), take_until(")}}}"), take(1usize)))(input)?;
         let (input, _) = tag("}}}")(input)?;
 
-        Ok((input, Element::Macros(Macros { name, arguments })))
+        Ok((
+            input,
+            Element::Macros(Macros {
+                name: name.into(),
+                arguments: arguments.map(Into::into),
+            }),
+        ))
     }
 }
 
@@ -38,8 +46,8 @@ fn parse() {
         Ok((
             "",
             Element::Macros(Macros {
-                name: "poem",
-                arguments: Some("red,blue")
+                name: "poem".into(),
+                arguments: Some("red,blue".into())
             })
         ))
     );
@@ -48,8 +56,8 @@ fn parse() {
         Ok((
             "",
             Element::Macros(Macros {
-                name: "poem",
-                arguments: Some(")")
+                name: "poem".into(),
+                arguments: Some(")".into())
             })
         ))
     );
@@ -58,7 +66,7 @@ fn parse() {
         Ok((
             "",
             Element::Macros(Macros {
-                name: "author",
+                name: "author".into(),
                 arguments: None
             })
         ))
diff --git a/src/elements/planning.rs b/src/elements/planning.rs
index 340ad42..95603f1 100644
--- a/src/elements/planning.rs
+++ b/src/elements/planning.rs
@@ -80,7 +80,7 @@ fn prase() {
                         year: 2019,
                         month: 4,
                         day: 8,
-                        dayname: "Mon",
+                        dayname: "Mon".into(),
                         hour: None,
                         minute: None
                     },
diff --git a/src/elements/snippet.rs b/src/elements/snippet.rs
index 3708fcc..a2baaf9 100644
--- a/src/elements/snippet.rs
+++ b/src/elements/snippet.rs
@@ -1,3 +1,5 @@
+use std::borrow::Cow;
+
 use nom::{
     bytes::complete::{tag, take_until, take_while1},
     sequence::{delimited, separated_pair},
@@ -10,8 +12,8 @@ use crate::elements::Element;
 #[cfg_attr(feature = "ser", derive(serde::Serialize))]
 #[derive(Debug)]
 pub struct Snippet<'a> {
-    pub name: &'a str,
-    pub value: &'a str,
+    pub name: Cow<'a, str>,
+    pub value: Cow<'a, str>,
 }
 
 impl Snippet<'_> {
@@ -27,7 +29,13 @@ impl Snippet<'_> {
             tag("@@"),
         )(input)?;
 
-        Ok((input, Element::Snippet(Snippet { name, value })))
+        Ok((
+            input,
+            Element::Snippet(Snippet {
+                name: name.into(),
+                value: value.into(),
+            }),
+        ))
     }
 }
 
@@ -38,8 +46,8 @@ fn parse() {
         Ok((
             "",
             Element::Snippet(Snippet {
-                name: "html",
-                value: "<b>"
+                name: "html".into(),
+                value: "<b>".into()
             })
         ))
     );
@@ -48,8 +56,8 @@ fn parse() {
         Ok((
             "",
             Element::Snippet(Snippet {
-                name: "latex",
-                value: "any arbitrary LaTeX code",
+                name: "latex".into(),
+                value: "any arbitrary LaTeX code".into(),
             })
         ))
     );
@@ -58,8 +66,8 @@ fn parse() {
         Ok((
             "",
             Element::Snippet(Snippet {
-                name: "html",
-                value: "",
+                name: "html".into(),
+                value: "".into(),
             })
         ))
     );
@@ -68,8 +76,8 @@ fn parse() {
         Ok((
             "",
             Element::Snippet(Snippet {
-                name: "html",
-                value: "<p>@</p>",
+                name: "html".into(),
+                value: "<p>@</p>".into(),
             })
         ))
     );
diff --git a/src/elements/table.rs b/src/elements/table.rs
index 815100f..4d58c72 100644
--- a/src/elements/table.rs
+++ b/src/elements/table.rs
@@ -1,12 +1,14 @@
+use std::borrow::Cow;
+
 #[derive(Debug)]
 #[cfg_attr(test, derive(PartialEq))]
 #[cfg_attr(feature = "ser", derive(serde::Serialize))]
 #[cfg_attr(feature = "ser", serde(tag = "table_type"))]
 pub enum Table<'a> {
     #[cfg_attr(feature = "ser", serde(rename = "org"))]
-    Org { tblfm: Option<&'a str> },
+    Org { tblfm: Option<Cow<'a, str>> },
     #[cfg_attr(feature = "ser", serde(rename = "table.el"))]
-    TableEl { value: &'a str },
+    TableEl { value: Cow<'a, str> },
 }
 
 #[derive(Debug)]
diff --git a/src/elements/target.rs b/src/elements/target.rs
index 7eb9d9e..49d4634 100644
--- a/src/elements/target.rs
+++ b/src/elements/target.rs
@@ -1,3 +1,5 @@
+use std::borrow::Cow;
+
 use nom::{
     bytes::complete::{tag, take_while},
     combinator::verify,
@@ -11,7 +13,7 @@ use crate::elements::Element;
 #[cfg_attr(feature = "ser", derive(serde::Serialize))]
 #[derive(Debug)]
 pub struct Target<'a> {
-    pub target: &'a str,
+    pub target: Cow<'a, str>,
 }
 
 impl Target<'_> {
@@ -26,7 +28,12 @@ impl Target<'_> {
             tag(">>"),
         )(input)?;
 
-        Ok((input, Element::Target(Target { target })))
+        Ok((
+            input,
+            Element::Target(Target {
+                target: target.into(),
+            }),
+        ))
     }
 }
 
@@ -34,11 +41,21 @@ impl Target<'_> {
 fn parse() {
     assert_eq!(
         Target::parse("<<target>>"),
-        Ok(("", Element::Target(Target { target: "target" })))
+        Ok((
+            "",
+            Element::Target(Target {
+                target: "target".into()
+            })
+        ))
     );
     assert_eq!(
         Target::parse("<<tar get>>"),
-        Ok(("", Element::Target(Target { target: "tar get" })))
+        Ok((
+            "",
+            Element::Target(Target {
+                target: "tar get".into()
+            })
+        ))
     );
     assert!(Target::parse("<<target >>").is_err());
     assert!(Target::parse("<< target>>").is_err());
diff --git a/src/elements/timestamp.rs b/src/elements/timestamp.rs
index 345f7a4..e4a1dea 100644
--- a/src/elements/timestamp.rs
+++ b/src/elements/timestamp.rs
@@ -1,3 +1,5 @@
+use std::borrow::Cow;
+
 use nom::{
     bytes::complete::{tag, take, take_till, take_while, take_while_m_n},
     character::complete::{space0, space1},
@@ -21,7 +23,7 @@ pub struct Datetime<'a> {
     pub year: u16,
     pub month: u8,
     pub day: u8,
-    pub dayname: &'a str,
+    pub dayname: Cow<'a, str>,
     #[cfg_attr(feature = "ser", serde(skip_serializing_if = "Option::is_none"))]
     pub hour: Option<u8>,
     #[cfg_attr(feature = "ser", serde(skip_serializing_if = "Option::is_none"))]
@@ -64,7 +66,7 @@ fn parse_datetime(input: &str) -> IResult<&str, Datetime<'_>> {
             year,
             month,
             day,
-            dayname,
+            dayname: dayname.into(),
             hour,
             minute,
         },
@@ -114,35 +116,35 @@ pub enum Timestamp<'a> {
     Active {
         start: Datetime<'a>,
         #[cfg_attr(feature = "ser", serde(skip_serializing_if = "Option::is_none"))]
-        repeater: Option<&'a str>,
+        repeater: Option<Cow<'a, str>>,
         #[cfg_attr(feature = "ser", serde(skip_serializing_if = "Option::is_none"))]
-        delay: Option<&'a str>,
+        delay: Option<Cow<'a, str>>,
     },
     Inactive {
         start: Datetime<'a>,
         #[cfg_attr(feature = "ser", serde(skip_serializing_if = "Option::is_none"))]
-        repeater: Option<&'a str>,
+        repeater: Option<Cow<'a, str>>,
         #[cfg_attr(feature = "ser", serde(skip_serializing_if = "Option::is_none"))]
-        delay: Option<&'a str>,
+        delay: Option<Cow<'a, str>>,
     },
     ActiveRange {
         start: Datetime<'a>,
         end: Datetime<'a>,
         #[cfg_attr(feature = "ser", serde(skip_serializing_if = "Option::is_none"))]
-        repeater: Option<&'a str>,
+        repeater: Option<Cow<'a, str>>,
         #[cfg_attr(feature = "ser", serde(skip_serializing_if = "Option::is_none"))]
-        delay: Option<&'a str>,
+        delay: Option<Cow<'a, str>>,
     },
     InactiveRange {
         start: Datetime<'a>,
         end: Datetime<'a>,
         #[cfg_attr(feature = "ser", serde(skip_serializing_if = "Option::is_none"))]
-        repeater: Option<&'a str>,
+        repeater: Option<Cow<'a, str>>,
         #[cfg_attr(feature = "ser", serde(skip_serializing_if = "Option::is_none"))]
-        delay: Option<&'a str>,
+        delay: Option<Cow<'a, str>>,
     },
     Diary {
-        value: &'a str,
+        value: Cow<'a, str>,
     },
 }
 
@@ -258,7 +260,12 @@ impl Timestamp<'_> {
         let (input, value) = take_till(|c| c == ')' || c == '>' || c == '\n')(input)?;
         let (input, _) = tag(")>")(input)?;
 
-        Ok((input, Timestamp::Diary { value }))
+        Ok((
+            input,
+            Timestamp::Diary {
+                value: value.into(),
+            },
+        ))
     }
 }
 
@@ -320,7 +327,7 @@ fn parse() {
                     year: 2003,
                     month: 9,
                     day: 16,
-                    dayname: "Tue",
+                    dayname: "Tue".into(),
                     hour: None,
                     minute: None
                 },
@@ -338,7 +345,7 @@ fn parse() {
                     year: 2003,
                     month: 9,
                     day: 16,
-                    dayname: "Tue",
+                    dayname: "Tue".into(),
                     hour: Some(9),
                     minute: Some(39)
                 },
@@ -346,7 +353,7 @@ fn parse() {
                     year: 2003,
                     month: 9,
                     day: 16,
-                    dayname: "Tue",
+                    dayname: "Tue".into(),
                     hour: Some(10),
                     minute: Some(39),
                 },
@@ -364,7 +371,7 @@ fn parse() {
                     year: 2003,
                     month: 9,
                     day: 16,
-                    dayname: "Tue",
+                    dayname: "Tue".into(),
                     hour: Some(9),
                     minute: Some(39),
                 },
@@ -372,7 +379,7 @@ fn parse() {
                     year: 2003,
                     month: 9,
                     day: 16,
-                    dayname: "Tue",
+                    dayname: "Tue".into(),
                     hour: Some(10),
                     minute: Some(39),
                 },
diff --git a/src/elements/title.rs b/src/elements/title.rs
index 814dcb3..5e0a72e 100644
--- a/src/elements/title.rs
+++ b/src/elements/title.rs
@@ -1,14 +1,17 @@
 //! Headline Title
 
+use std::borrow::Cow;
+
 use memchr::memrchr;
 use nom::{
     bytes::complete::{tag, take_until, take_while},
     character::complete::{anychar, space1},
     combinator::{map, map_parser, opt, verify},
+    error::ErrorKind,
+    error_position,
     multi::fold_many0,
-    sequence::delimited,
-    sequence::preceded,
-    IResult,
+    sequence::{delimited, preceded},
+    Err, IResult,
 };
 use std::collections::HashMap;
 
@@ -27,20 +30,23 @@ pub struct Title<'a> {
     pub priority: Option<char>,
     /// headline tags, including the sparated colons
     #[cfg_attr(feature = "ser", serde(skip_serializing_if = "Vec::is_empty"))]
-    pub tags: Vec<&'a str>,
+    pub tags: Vec<Cow<'a, str>>,
     /// headline keyword
     #[cfg_attr(feature = "ser", serde(skip_serializing_if = "Option::is_none"))]
-    pub keyword: Option<&'a str>,
-    pub raw: &'a str,
+    pub keyword: Option<Cow<'a, str>>,
+    pub raw: Cow<'a, str>,
     #[cfg_attr(feature = "ser", serde(skip_serializing_if = "Option::is_none"))]
     pub planning: Option<Box<Planning<'a>>>,
     #[cfg_attr(feature = "ser", serde(skip_serializing_if = "HashMap::is_empty"))]
-    pub properties: HashMap<&'a str, &'a str>,
+    pub properties: HashMap<Cow<'a, str>, Cow<'a, str>>,
 }
 
 impl Title<'_> {
     #[inline]
-    pub(crate) fn parse<'a>(input: &'a str, config: &ParseConfig) -> IResult<&'a str, Title<'a>> {
+    pub(crate) fn parse<'a>(
+        input: &'a str,
+        config: &ParseConfig,
+    ) -> IResult<&'a str, (Title<'a>, &'a str)> {
         let (input, (level, keyword, priority, raw, tags)) = parse_headline(input, config)?;
 
         let (input, planning) = Planning::parse(input)
@@ -51,15 +57,18 @@ impl Title<'_> {
 
         Ok((
             input,
-            Title {
-                properties: properties.unwrap_or_default(),
-                level,
-                keyword,
-                priority,
-                tags,
+            (
+                Title {
+                    properties: properties.unwrap_or_default(),
+                    level,
+                    keyword: keyword.map(Into::into),
+                    priority,
+                    tags,
+                    raw: raw.into(),
+                    planning,
+                },
                 raw,
-                planning,
-            },
+            ),
         ))
     }
 }
@@ -67,7 +76,16 @@ impl Title<'_> {
 fn parse_headline<'a>(
     input: &'a str,
     config: &ParseConfig,
-) -> IResult<&'a str, (usize, Option<&'a str>, Option<char>, &'a str, Vec<&'a str>)> {
+) -> IResult<
+    &'a str,
+    (
+        usize,
+        Option<&'a str>,
+        Option<char>,
+        &'a str,
+        Vec<Cow<'a, str>>,
+    ),
+> {
     let (input, level) = map(take_while(|c: char| c == '*'), |s: &str| s.len())(input)?;
 
     debug_assert!(level > 0);
@@ -103,19 +121,24 @@ fn parse_headline<'a>(
             keyword,
             priority,
             raw,
-            tags.split(':').filter(|s| !s.is_empty()).collect(),
+            tags.split(':')
+                .filter(|s| !s.is_empty())
+                .map(Into::into)
+                .collect(),
         ),
     ))
 }
 
-fn parse_properties_drawer(input: &str) -> IResult<&str, HashMap<&str, &str>> {
+fn parse_properties_drawer(input: &str) -> IResult<&str, HashMap<Cow<'_, str>, Cow<'_, str>>> {
     let (input, (drawer, content)) = Drawer::parse(input)?;
-    let _ = tag("PROPERTIES")(drawer.name)?;
+    if drawer.name != "PROPERTIES" {
+        return Err(Err::Error(error_position!(input, ErrorKind::Tag)));
+    }
     let (_, map) = fold_many0(
         parse_node_property,
         HashMap::new(),
         |mut acc: HashMap<_, _>, (name, value)| {
-            acc.insert(name, value);
+            acc.insert(name.into(), value.into());
             acc
         },
     )(content)?;
@@ -134,7 +157,7 @@ fn parse_node_property(input: &str) -> IResult<&str, (&str, &str)> {
 impl Title<'_> {
     /// checks if this headline is "archived"
     pub fn is_archived(&self) -> bool {
-        self.tags.contains(&"ARCHIVE")
+        self.tags.iter().any(|tag| tag == "ARCHIVE")
     }
 }
 
@@ -154,7 +177,7 @@ fn parse_headline_() {
                 Some("DONE"),
                 Some('A'),
                 "COMMENT Title",
-                vec!["tag", "a2%"]
+                vec!["tag".into(), "a2%".into()]
             )
         ))
     );
diff --git a/src/export/html.rs b/src/export/html.rs
index a07a126..9f4d25a 100644
--- a/src/export/html.rs
+++ b/src/export/html.rs
@@ -3,14 +3,14 @@ use jetscii::bytes;
 use std::fmt;
 use std::io::{Error, Write};
 
-pub struct Escape<'a>(pub &'a str);
+pub struct Escape<S: AsRef<str>>(pub S);
 
-impl fmt::Display for Escape<'_> {
+impl<S: AsRef<str>> fmt::Display for Escape<S> {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         let mut pos = 0;
-        let bytes = self.0.as_bytes();
+        let bytes = self.0.as_ref().as_bytes();
         while let Some(off) = bytes!(b'<', b'>', b'&', b'\'', b'"').find(&bytes[pos..]) {
-            write!(f, "{}", &self.0[pos..pos + off])?;
+            write!(f, "{}", &self.0.as_ref()[pos..pos + off])?;
 
             pos += off + 1;
 
@@ -24,7 +24,7 @@ impl fmt::Display for Escape<'_> {
             }
         }
 
-        write!(f, "{}", &self.0[pos..])
+        write!(f, "{}", &self.0.as_ref()[pos..])
     }
 }
 
@@ -57,9 +57,11 @@ pub trait HtmlHandler<E: From<Error>> {
             Underline => write!(w, "<u>")?,
             // non-container elements
             CommentBlock(_) => (),
-            ExampleBlock(block) => {
-                write!(w, "<pre class=\"example\">{}</pre>", Escape(block.contents))?
-            }
+            ExampleBlock(block) => write!(
+                w,
+                "<pre class=\"example\">{}</pre>",
+                Escape(&block.contents)
+            )?,
             ExportBlock(block) => {
                 if block.data.eq_ignore_ascii_case("HTML") {
                     write!(w, "{}", block.contents)?
@@ -67,13 +69,17 @@ pub trait HtmlHandler<E: From<Error>> {
             }
             SourceBlock(block) => {
                 if block.language.is_empty() {
-                    write!(w, "<pre class=\"example\">{}</pre>", Escape(block.contents))?;
+                    write!(
+                        w,
+                        "<pre class=\"example\">{}</pre>",
+                        Escape(&block.contents)
+                    )?;
                 } else {
                     write!(
                         w,
                         "<div class=\"org-src-container\"><pre class=\"src src-{}\">{}</pre></div>",
                         block.language,
-                        Escape(block.contents)
+                        Escape(&block.contents)
                     )?;
                 }
             }
@@ -82,7 +88,7 @@ pub trait HtmlHandler<E: From<Error>> {
                 w,
                 "<code class=\"src src-{}\">{}</code>",
                 inline_src.lang,
-                Escape(inline_src.body)
+                Escape(&inline_src.body)
             )?,
             Code { value } => write!(w, "<code>{}</code>", Escape(value))?,
             FnRef(_fn_ref) => (),
@@ -90,8 +96,8 @@ pub trait HtmlHandler<E: From<Error>> {
             Link(link) => write!(
                 w,
                 "<a href=\"{}\">{}</a>",
-                Escape(link.path),
-                Escape(link.desc.unwrap_or(link.path)),
+                Escape(&link.path),
+                Escape(link.desc.as_ref().unwrap_or(&link.path)),
             )?,
             Macros(_macros) => (),
             RadioTarget(_radio_target) => (),
diff --git a/src/export/org.rs b/src/export/org.rs
index fff11fe..2bbad38 100644
--- a/src/export/org.rs
+++ b/src/export/org.rs
@@ -15,7 +15,7 @@ pub trait OrgHandler<E: From<Error>> {
             Document => (),
             DynBlock(dyn_block) => {
                 write!(&mut w, "#+BEGIN: {}", dyn_block.block_name)?;
-                if let Some(parameters) = dyn_block.arguments {
+                if let Some(parameters) = &dyn_block.arguments {
                     write!(&mut w, " {}", parameters)?;
                 }
                 writeln!(&mut w)?;
@@ -49,7 +49,7 @@ pub trait OrgHandler<E: From<Error>> {
             BabelCall(_babel_call) => (),
             InlineSrc(inline_src) => {
                 write!(&mut w, "src_{}", inline_src.lang)?;
-                if let Some(options) = inline_src.options {
+                if let Some(options) = &inline_src.options {
                     write!(&mut w, "[{}]", options)?;
                 }
                 write!(&mut w, "{{{}}}", inline_src.body)?;
@@ -57,24 +57,24 @@ pub trait OrgHandler<E: From<Error>> {
             Code { value } => write!(w, "~{}~", value)?,
             FnRef(fn_ref) => {
                 write!(&mut w, "[fn:{}", fn_ref.label)?;
-                if let Some(definition) = fn_ref.definition {
+                if let Some(definition) = &fn_ref.definition {
                     write!(&mut w, ":{}", definition)?;
                 }
                 write!(&mut w, "]")?;
             }
             InlineCall(inline_call) => {
                 write!(&mut w, "call_{}", inline_call.name)?;
-                if let Some(header) = inline_call.inside_header {
+                if let Some(header) = &inline_call.inside_header {
                     write!(&mut w, "[{}]", header)?;
                 }
                 write!(&mut w, "({})", inline_call.arguments)?;
-                if let Some(header) = inline_call.end_header {
+                if let Some(header) = &inline_call.end_header {
                     write!(&mut w, "[{}]", header)?;
                 }
             }
             Link(link) => {
                 write!(&mut w, "[[{}]", link.path)?;
-                if let Some(desc) = link.desc {
+                if let Some(desc) = &link.desc {
                     write!(&mut w, "[{}]", desc)?;
                 }
                 write!(&mut w, "]")?;
@@ -130,7 +130,7 @@ pub trait OrgHandler<E: From<Error>> {
             FixedWidth { value } => write!(w, "{}", value)?,
             Keyword(keyword) => {
                 write!(&mut w, "#+{}", keyword.key)?;
-                if let Some(optional) = keyword.optional {
+                if let Some(optional) = &keyword.optional {
                     write!(&mut w, "[{}]", optional)?;
                 }
                 writeln!(&mut w, ": {}", keyword.value)?;
@@ -141,7 +141,7 @@ pub trait OrgHandler<E: From<Error>> {
                 for _ in 0..title.level {
                     write!(&mut w, "*")?;
                 }
-                if let Some(keyword) = title.keyword {
+                if let Some(keyword) = &title.keyword {
                     write!(&mut w, " {}", keyword)?;
                 }
                 if let Some(priority) = title.priority {
diff --git a/src/lib.rs b/src/lib.rs
index 0c2773d..c66b6dd 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -125,7 +125,7 @@
 //!                         w,
 //!                         "<h{0}><a id=\"{1}\" href=\"#{1}\">",
 //!                         title.level,
-//!                         slugify!(title.raw),
+//!                         slugify!(&title.raw),
 //!                     )?;
 //!                 }
 //!             }
diff --git a/src/parsers.rs b/src/parsers.rs
index cc16b7b..a91ac33 100644
--- a/src/parsers.rs
+++ b/src/parsers.rs
@@ -10,6 +10,7 @@ use nom::{
     error::ErrorKind,
     error_position, Err, IResult,
 };
+use std::borrow::Cow;
 
 use crate::config::ParseConfig;
 use crate::elements::*;
@@ -50,8 +51,7 @@ pub fn parse_title<'a>(
     containers: &mut Vec<Container<'a>>,
     config: &ParseConfig,
 ) -> &'a str {
-    let (tail, title) = Title::parse(content, config).unwrap();
-    let content = title.raw;
+    let (tail, (title, content)) = Title::parse(content, config).unwrap();
     let node = arena.new_node(Element::Title(title));
     parent.append(node, arena);
     containers.push(Container::Inline { content, node });
@@ -294,33 +294,42 @@ pub fn parse_block<'a>(
                 "COMMENT" => {
                     let node = arena.new_node(Element::CommentBlock(CommentBlock {
                         data: block.args,
-                        contents: content,
+                        contents: content.into(),
                     }));
                     Some((tail, node))
                 }
                 "EXAMPLE" => {
                     let node = arena.new_node(Element::ExampleBlock(ExampleBlock {
                         data: block.args,
-                        contents: content,
+                        contents: content.into(),
                     }));
                     Some((tail, node))
                 }
                 "EXPORT" => {
                     let node = arena.new_node(Element::ExportBlock(ExportBlock {
-                        data: block.args.unwrap_or(""),
-                        contents: content,
+                        data: block.args.unwrap_or_default(),
+                        contents: content.into(),
                     }));
                     Some((tail, node))
                 }
                 "SRC" => {
-                    let (language, arguments) = block
-                        .args
-                        .map(|args| args.split_at(args.find(' ').unwrap_or_else(|| args.len())))
-                        .unwrap_or(("", ""));
+                    let (language, arguments) = match &block.args {
+                        Some(Cow::Borrowed(args)) => {
+                            let (language, arguments) =
+                                args.split_at(args.find(' ').unwrap_or_else(|| args.len()));
+                            (Cow::Borrowed(language), Cow::Borrowed(arguments))
+                        }
+                        Some(Cow::Owned(args)) => {
+                            let (language, arguments) =
+                                args.split_at(args.find(' ').unwrap_or_else(|| args.len()));
+                            (Cow::Owned(language.into()), Cow::Owned(arguments.into()))
+                        }
+                        None => (Cow::Borrowed(""), Cow::Borrowed("")),
+                    };
                     let node = arena.new_node(Element::SourceBlock(SourceBlock {
                         arguments,
                         language,
-                        contents: content,
+                        contents: content.into(),
                     }));
                     Some((tail, node))
                 }
@@ -605,7 +614,7 @@ pub fn prase_table<'a>(
                     Some((
                         &contents[last_end..],
                         arena.new_node(Element::Table(Table::TableEl {
-                            value: &contents[0..last_end],
+                            value: contents[0..last_end].into(),
                         })),
                     ))
                 };
@@ -615,7 +624,9 @@ pub fn prase_table<'a>(
 
         Some((
             "",
-            arena.new_node(Element::Table(Table::TableEl { value: contents })),
+            arena.new_node(Element::Table(Table::TableEl {
+                value: contents.into(),
+            })),
         ))
     } else {
         None