<section name="Release 12.1.0">

<div class="releaseDate">19.10.2025</div>

<p>New:</p>

<ul>

<li>

New check: HexLiteralCase, Hexadecimal literals should use upper case letters A-F.

Author: zyad

<a href="https://github.com/checkstyle/checkstyle/issues/16836">#16836</a>

</li>

</ul>

<p>Notes:</p>

<ul>

<li>

Add missing property examples to XDocs for Checkstyle Checks.

Author: JANHVI BABANI

<a href="https://github.com/checkstyle/checkstyle/issues/17449">#17449</a>

</li>

<li>

Resolve error-prone violations.

Author: atharv

<a href="https://github.com/checkstyle/checkstyle/issues/17845">#17845</a>

</li>

<li>

Update `JavadocCommentsTokenTypes.java` to new format of AST print.

Author: Andrei Mititelu, ivanmalutin, ANISETTY AKASH

<a href="https://github.com/checkstyle/checkstyle/issues/17882">#17882</a>

</li>

<li>

Convert eligible classes to records.

Author: atharv

<a href="https://github.com/checkstyle/checkstyle/issues/17299">#17299</a>

</li>

<li>

test to check indentation trailing comments are vertically aligned.

Author: voidCounter, Kishor

<a href="https://github.com/checkstyle/checkstyle/issues/17128">#17128</a>

</li>

<li>

update JavadocTokenTypes.java to new format of AST print.

Author: Talib Hussain

<a href="https://github.com/checkstyle/checkstyle/issues/14631">#14631</a>

</li>

<li>

CheckstyleAntTaskTest.testNoFileOrPathSpecified not executed because it&#39;s static.

Author: Allon Mureinik

<a href="https://github.com/checkstyle/checkstyle/issues/17924">#17924</a>

</li>

<li>

Resolving spotbugs violations.

Author: atharv

<a href="https://github.com/checkstyle/checkstyle/issues/17933">#17933</a>

</li>

<li>

Remove ImportControlTest supressions.

Author: Allon Mureinik

<a href="https://github.com/checkstyle/checkstyle/issues/17910">#17910</a>

</li>

<li>

Deploy configuration-1-3.xsd to the CheckStyle website.

Author: Sockalingam

<a href="https://github.com/checkstyle/checkstyle/issues/17865">#17865</a>

</li>

<li>

Add `id` to `NeedBraces` declaration.

Author: Vincent Potucek

<a href="https://github.com/checkstyle/checkstyle/issues/17891">#17891</a>

</li>

</ul>

</section>