File: vendor/squizlabs/php_codesniffer/src/Standards/Generic/Docs/Classes/DuplicateClassNameStandard.xml

<documentation title="Duplicate Class Names">
    <standard>
    <![CDATA[
    Class and Interface names should be unique in a project.  They should never be duplicated.
    ]]>
    </standard>
    <code_comparison>
        <code title="Valid: A unique class name.">
        <![CDATA[
class <em>Foo</em>
{
}
        ]]>
        </code>
        <code title="Invalid: A class duplicated (including across multiple files).">
        <![CDATA[
class <em>Foo</em>
{
}

class <em>Foo</em>
{
}
        ]]>
        </code>
    </code_comparison>
</documentation>