Input format: note about include! macros

Author: mattheww

src/input-format.md

@@ -37,10 +37,16 @@ fn main() {
 As an exception, if the `#!` characters are followed (ignoring intervening [comments] or [whitespace]) by a `[` token, nothing is removed.
 This prevents an [inner attribute] at the start of a source file being removed.
 
+> **Note**: The standard library [`include!`] macro applies byte order mark removal, CRLF normalization, and shebang removal to the file it reads. The [`include_str!`] and [`include_bytes!`] macros do not.
+
 ## Tokenization
 
 The resulting sequence of characters is then converted into tokens as described in the remainder of this chapter.
 
+
+[`include!`]: ../std/macro.include.md
+[`include_bytes!`]: ../std/macro.include_bytes.md
+[`include_str!`]: ../std/macro.include_str.md
 [inner attribute]: attributes.md
 [BYTE ORDER MARK]: https://en.wikipedia.org/wiki/Byte_order_mark#UTF-8
 [comments]: comments.md