diff --git a/src/parser/citation.rs b/src/parser/citation.rs
index 0abb625c..13acca0e 100644
--- a/src/parser/citation.rs
+++ b/src/parser/citation.rs
@@ -12,6 +12,7 @@ use nom::multi::separated_list1;
 use nom::sequence::tuple;
 
 use super::citation_reference::must_balance_bracket;
+use super::org_source::BracketDepth;
 use super::org_source::OrgSource;
 use super::Context;
 use crate::error::CustomError;
@@ -102,7 +103,7 @@ fn global_prefix<'r, 's>(
 }
 
 fn global_prefix_end(
-    starting_bracket_depth: i16,
+    starting_bracket_depth: BracketDepth,
 ) -> impl for<'r, 's> Fn(Context<'r, 's>, OrgSource<'s>) -> Res<OrgSource<'s>, OrgSource<'s>> {
     move |context: Context, input: OrgSource<'_>| {
         _global_prefix_end(context, input, starting_bracket_depth)
@@ -113,7 +114,7 @@ fn global_prefix_end(
 fn _global_prefix_end<'r, 's>(
     context: Context<'r, 's>,
     input: OrgSource<'s>,
-    starting_bracket_depth: i16,
+    starting_bracket_depth: BracketDepth,
 ) -> Res<OrgSource<'s>, OrgSource<'s>> {
     let current_depth = input.get_bracket_depth() - starting_bracket_depth;
     if current_depth < 0 {
@@ -154,7 +155,7 @@ fn global_suffix<'r, 's>(
 }
 
 fn global_suffix_end(
-    starting_bracket_depth: i16,
+    starting_bracket_depth: BracketDepth,
 ) -> impl for<'r, 's> Fn(Context<'r, 's>, OrgSource<'s>) -> Res<OrgSource<'s>, OrgSource<'s>> {
     move |context: Context, input: OrgSource<'_>| {
         _global_suffix_end(context, input, starting_bracket_depth)
@@ -165,7 +166,7 @@ fn global_suffix_end(
 fn _global_suffix_end<'r, 's>(
     context: Context<'r, 's>,
     input: OrgSource<'s>,
-    starting_bracket_depth: i16,
+    starting_bracket_depth: BracketDepth,
 ) -> Res<OrgSource<'s>, OrgSource<'s>> {
     let current_depth = input.get_bracket_depth() - starting_bracket_depth;
     if current_depth < 0 {
diff --git a/src/parser/citation_reference.rs b/src/parser/citation_reference.rs
index ff560cf5..0024fc3c 100644
--- a/src/parser/citation_reference.rs
+++ b/src/parser/citation_reference.rs
@@ -10,6 +10,7 @@ use nom::multi::many_till;
 use nom::sequence::preceded;
 use nom::sequence::tuple;
 
+use super::org_source::BracketDepth;
 use super::org_source::OrgSource;
 use super::Context;
 use crate::error::CustomError;
@@ -109,7 +110,7 @@ fn key_suffix<'r, 's>(
 }
 
 fn key_prefix_end(
-    starting_bracket_depth: i16,
+    starting_bracket_depth: BracketDepth,
 ) -> impl for<'r, 's> Fn(Context<'r, 's>, OrgSource<'s>) -> Res<OrgSource<'s>, OrgSource<'s>> {
     move |context: Context, input: OrgSource<'_>| {
         _key_prefix_end(context, input, starting_bracket_depth)
@@ -120,7 +121,7 @@ fn key_prefix_end(
 fn _key_prefix_end<'r, 's>(
     context: Context<'r, 's>,
     input: OrgSource<'s>,
-    starting_bracket_depth: i16,
+    starting_bracket_depth: BracketDepth,
 ) -> Res<OrgSource<'s>, OrgSource<'s>> {
     let current_depth = input.get_bracket_depth() - starting_bracket_depth;
     if current_depth < 0 {
@@ -140,7 +141,7 @@ fn _key_prefix_end<'r, 's>(
 }
 
 fn key_suffix_end(
-    starting_bracket_depth: i16,
+    starting_bracket_depth: BracketDepth,
 ) -> impl for<'r, 's> Fn(Context<'r, 's>, OrgSource<'s>) -> Res<OrgSource<'s>, OrgSource<'s>> {
     move |context: Context, input: OrgSource<'_>| {
         _key_suffix_end(context, input, starting_bracket_depth)
@@ -151,7 +152,7 @@ fn key_suffix_end(
 fn _key_suffix_end<'r, 's>(
     _context: Context<'r, 's>,
     input: OrgSource<'s>,
-    starting_bracket_depth: i16,
+    starting_bracket_depth: BracketDepth,
 ) -> Res<OrgSource<'s>, OrgSource<'s>> {
     let current_depth = input.get_bracket_depth() - starting_bracket_depth;
     if current_depth < 0 {
diff --git a/src/parser/footnote_reference.rs b/src/parser/footnote_reference.rs
index a26610c2..2de9a126 100644
--- a/src/parser/footnote_reference.rs
+++ b/src/parser/footnote_reference.rs
@@ -5,6 +5,7 @@ use nom::character::complete::space0;
 use nom::combinator::verify;
 use nom::multi::many_till;
 
+use super::org_source::BracketDepth;
 use super::org_source::OrgSource;
 use super::parser_context::ContextElement;
 use super::Context;
@@ -121,7 +122,7 @@ fn footnote_reference_only<'r, 's>(
 }
 
 fn footnote_definition_end(
-    starting_bracket_depth: i16,
+    starting_bracket_depth: BracketDepth,
 ) -> impl for<'r, 's> Fn(Context<'r, 's>, OrgSource<'s>) -> Res<OrgSource<'s>, OrgSource<'s>> {
     move |context: Context, input: OrgSource<'_>| {
         _footnote_definition_end(context, input, starting_bracket_depth)
@@ -132,7 +133,7 @@ fn footnote_definition_end(
 fn _footnote_definition_end<'r, 's>(
     _context: Context<'r, 's>,
     input: OrgSource<'s>,
-    starting_bracket_depth: i16,
+    starting_bracket_depth: BracketDepth,
 ) -> Res<OrgSource<'s>, OrgSource<'s>> {
     let current_depth = input.get_bracket_depth() - starting_bracket_depth;
     if current_depth > 0 {
diff --git a/src/parser/inline_babel_call.rs b/src/parser/inline_babel_call.rs
index c4f22000..1f17b96e 100644
--- a/src/parser/inline_babel_call.rs
+++ b/src/parser/inline_babel_call.rs
@@ -10,6 +10,7 @@ use nom::combinator::recognize;
 use nom::combinator::verify;
 use nom::multi::many_till;
 
+use super::org_source::BracketDepth;
 use super::org_source::OrgSource;
 use super::Context;
 use crate::error::CustomError;
@@ -91,7 +92,7 @@ fn header<'r, 's>(
 }
 
 fn header_end(
-    starting_bracket_depth: i16,
+    starting_bracket_depth: BracketDepth,
 ) -> impl for<'r, 's> Fn(Context<'r, 's>, OrgSource<'s>) -> Res<OrgSource<'s>, OrgSource<'s>> {
     move |context: Context, input: OrgSource<'_>| {
         _header_end(context, input, starting_bracket_depth)
@@ -102,7 +103,7 @@ fn header_end(
 fn _header_end<'r, 's>(
     _context: Context<'r, 's>,
     input: OrgSource<'s>,
-    starting_bracket_depth: i16,
+    starting_bracket_depth: BracketDepth,
 ) -> Res<OrgSource<'s>, OrgSource<'s>> {
     let current_depth = input.get_bracket_depth() - starting_bracket_depth;
     if current_depth > 0 {
@@ -141,7 +142,7 @@ fn argument<'r, 's>(
 }
 
 fn argument_end(
-    starting_parenthesis_depth: i16,
+    starting_parenthesis_depth: BracketDepth,
 ) -> impl for<'r, 's> Fn(Context<'r, 's>, OrgSource<'s>) -> Res<OrgSource<'s>, OrgSource<'s>> {
     move |context: Context, input: OrgSource<'_>| {
         _argument_end(context, input, starting_parenthesis_depth)
@@ -152,7 +153,7 @@ fn argument_end(
 fn _argument_end<'r, 's>(
     _context: Context<'r, 's>,
     input: OrgSource<'s>,
-    starting_parenthesis_depth: i16,
+    starting_parenthesis_depth: BracketDepth,
 ) -> Res<OrgSource<'s>, OrgSource<'s>> {
     let current_depth = input.get_parenthesis_depth() - starting_parenthesis_depth;
     if current_depth > 0 {
diff --git a/src/parser/inline_source_block.rs b/src/parser/inline_source_block.rs
index e07d67da..bde53ee3 100644
--- a/src/parser/inline_source_block.rs
+++ b/src/parser/inline_source_block.rs
@@ -12,6 +12,7 @@ use nom::multi::many_till;
 #[cfg(feature = "tracing")]
 use tracing::span;
 
+use super::org_source::BracketDepth;
 use super::org_source::OrgSource;
 use super::Context;
 use crate::error::CustomError;
@@ -92,7 +93,7 @@ fn header<'r, 's>(
 }
 
 fn header_end(
-    starting_bracket_depth: i16,
+    starting_bracket_depth: BracketDepth,
 ) -> impl for<'r, 's> Fn(Context<'r, 's>, OrgSource<'s>) -> Res<OrgSource<'s>, OrgSource<'s>> {
     move |context: Context, input: OrgSource<'_>| {
         _header_end(context, input, starting_bracket_depth)
@@ -103,7 +104,7 @@ fn header_end(
 fn _header_end<'r, 's>(
     _context: Context<'r, 's>,
     input: OrgSource<'s>,
-    starting_bracket_depth: i16,
+    starting_bracket_depth: BracketDepth,
 ) -> Res<OrgSource<'s>, OrgSource<'s>> {
     let current_depth = input.get_bracket_depth() - starting_bracket_depth;
     if current_depth > 0 {
@@ -152,7 +153,7 @@ fn body<'r, 's>(
 }
 
 fn body_end(
-    starting_brace_depth: i16,
+    starting_brace_depth: BracketDepth,
 ) -> impl for<'r, 's> Fn(Context<'r, 's>, OrgSource<'s>) -> Res<OrgSource<'s>, OrgSource<'s>> {
     move |context: Context, input: OrgSource<'_>| _body_end(context, input, starting_brace_depth)
 }
@@ -161,7 +162,7 @@ fn body_end(
 fn _body_end<'r, 's>(
     _context: Context<'r, 's>,
     input: OrgSource<'s>,
-    starting_brace_depth: i16,
+    starting_brace_depth: BracketDepth,
 ) -> Res<OrgSource<'s>, OrgSource<'s>> {
     let current_depth = input.get_brace_depth() - starting_brace_depth;
     if current_depth > 0 {
diff --git a/src/parser/org_source.rs b/src/parser/org_source.rs
index 877c5564..231cb105 100644
--- a/src/parser/org_source.rs
+++ b/src/parser/org_source.rs
@@ -11,15 +11,17 @@ use nom::Slice;
 use crate::error::CustomError;
 use crate::error::MyError;
 
+pub type BracketDepth = i16;
+
 #[derive(Copy, Clone)]
 pub struct OrgSource<'s> {
     full_source: &'s str,
     start: usize,
     end: usize, // exclusive
     start_of_line: usize,
-    bracket_depth: i16,     // []
-    brace_depth: i16,       // {}
-    parenthesis_depth: i16, // ()
+    bracket_depth: BracketDepth,     // []
+    brace_depth: BracketDepth,       // {}
+    parenthesis_depth: BracketDepth, // ()
     preceding_character: Option<char>,
 }
 
@@ -71,15 +73,15 @@ impl<'s> OrgSource<'s> {
         self.slice(..(other.start - self.start))
     }
 
-    pub fn get_bracket_depth(&self) -> i16 {
+    pub fn get_bracket_depth(&self) -> BracketDepth {
         self.bracket_depth
     }
 
-    pub fn get_brace_depth(&self) -> i16 {
+    pub fn get_brace_depth(&self) -> BracketDepth {
         self.brace_depth
     }
 
-    pub fn get_parenthesis_depth(&self) -> i16 {
+    pub fn get_parenthesis_depth(&self) -> BracketDepth {
         self.parenthesis_depth
     }
 }
diff --git a/src/parser/subscript_and_superscript.rs b/src/parser/subscript_and_superscript.rs
index 93361ab3..52d518a7 100644
--- a/src/parser/subscript_and_superscript.rs
+++ b/src/parser/subscript_and_superscript.rs
@@ -11,6 +11,7 @@ use nom::combinator::recognize;
 use nom::combinator::verify;
 use nom::multi::many_till;
 
+use super::org_source::BracketDepth;
 use super::org_source::OrgSource;
 use super::Context;
 use super::Object;
@@ -170,7 +171,7 @@ fn script_with_braces<'r, 's>(
 }
 
 fn script_with_braces_end(
-    starting_brace_depth: i16,
+    starting_brace_depth: BracketDepth,
 ) -> impl for<'r, 's> Fn(Context<'r, 's>, OrgSource<'s>) -> Res<OrgSource<'s>, OrgSource<'s>> {
     move |context: Context, input: OrgSource<'_>| {
         _script_with_braces_end(context, input, starting_brace_depth)
@@ -181,7 +182,7 @@ fn script_with_braces_end(
 fn _script_with_braces_end<'r, 's>(
     _context: Context<'r, 's>,
     input: OrgSource<'s>,
-    starting_brace_depth: i16,
+    starting_brace_depth: BracketDepth,
 ) -> Res<OrgSource<'s>, OrgSource<'s>> {
     let current_depth = input.get_brace_depth() - starting_brace_depth;
     if current_depth > 0 {