A byte order mark may be disallowed anywhere else in the source.
</p>

<h3 id="Characters">Characters</h3>

<p>
The following terms are used to denote specific Unicode character classes:
</p>
<pre class="ebnf">
newline        = /* the Unicode code point U+000A */ .
unicode_char   = /* an arbitrary Unicode code point except newline */ .
unicode_letter = /* a Unicode code point classified as "Letter" */ .

A general comment containing no newlines acts like a space.
Any other comment acts like a newline.
</p>

<h3 id="Tokens">Tokens</h3>

<p>
Tokens form the vocabulary of the Go language.
There are four classes: <i>identifiers</i>, <i>keywords</i>, <i>operators
and punctuation</i>, and <i>literals</i>.  <i>White space</i>, formed from
spaces (U+0020), horizontal tabs (U+0009),
carriage returns (U+000D), and newlines (U+000A),