<!--{
"Title": "The Go Programming Language Specification",
- "Subtitle": "Version of September 4, 2012",
+ "Subtitle": "Version of September 6, 2012",
"Path": "/ref/spec"
}-->
Implementation restriction: For compatibility with other tools, a
compiler may disallow the NUL character (U+0000) in the source text.
</p>
+<p>
+Implementation restriction: For compatibility with other tools, a
+compiler may ignore any UTF-8-encoded Unicode byte order mark
+(U+FEFF) in the source text outside of <a href="#String_literals">string</a>
+and <a href="#Rune_literals">rune</a> literals.
+</p>
<h3 id="Characters">Characters</h3>