diff --git a/src/pgn/mod.rs b/src/pgn/mod.rs
index 2ee9776..283f024 100644
--- a/src/pgn/mod.rs
+++ b/src/pgn/mod.rs
@@ -210,7 +210,7 @@ pub fn parse_pgn(input_filename: &str) -> Result<Vec<PgnToken>, Box<dyn Error +
 
                 line_char_index += 1;
             } else if char == b'$' {
-                // TODO: Support NAG parsing
+                // TODO(#13): Support NAG parsing
 
                 while line_char_index < line_len && bytes[line_char_index] != b' ' {
                     line_char_index += 1;