Section 4.5 "General Category" defines a set of character categories.
Go treats all characters in any of the Letter categories Lu, Ll, Lt, Lm, or Lo
as Unicode letters, and those in the Number category Nd as Unicode digits.
</p>

<h3 id="Letters_and_digits">Letters and digits</h3>

<p>
The underscore character <code>_</code> (U+005F) is considered a lowercase letter.
</p>
<pre class="ebnf">

pkg unicode, var Meetei_Mayek *RangeTable
pkg unicode, var Mn *RangeTable
pkg unicode, var Mongolian *RangeTable
pkg unicode, var Myanmar *RangeTable
pkg unicode, var N *RangeTable
pkg unicode, var Nd *RangeTable
pkg unicode, var New_Tai_Lue *RangeTable
pkg unicode, var Nko *RangeTable
pkg unicode, var Nl *RangeTable
pkg unicode, var No *RangeTable
pkg unicode, var Noncharacter_Code_Point *RangeTable