custom_checks.xml

<?xml version="1.0"?>
<!DOCTYPE module PUBLIC
  "-//Checkstyle//DTD Checkstyle Configuration 1.3//EN"
  "https://checkstyle.org/dtds/configuration_1_3.dtd" [
  <!ENTITY indentSpaces "4">
  <!ENTITY namingRegEx "^[A-Z]$|^([a-z0-9]+[A-Z]?)*$">
  <!-- .... -->
]>
<module name="Checker">
  <!-- Filter out Checkstyle warnings that have been suppressed with the @SuppressWarnings annotation -->
  <module name="SuppressWarningsFilter" />
  <module name="TreeWalker">
    <!-- Make the @SuppressWarnings annotations available to Checkstyle -->
    <module name="SuppressWarningsHolder" />

    <!-- Suppressed google check, re-enabling here so can selectively suppress with annotation -->
    <module name="MultipleVariableDeclarations" />
    <module name="VariableDeclarationUsageDistanceCheck" />
    <module name="WhitespaceAround" />
    <module name="ParenPad" />

    <!-- indent spaces -->
    <module name="Indentation">
      <property name="basicOffset" value="&indentSpaces;" />
      <property name="braceAdjustment" value="&indentSpaces;" />
      <property name="caseIndent" value="&indentSpaces;" />
      <property name="throwsIndent" value="&indentSpaces;" />
      <property name="lineWrappingIndentation" value="&indentSpaces;" />
      <property name="arrayInitIndent" value="&indentSpaces;" />
    </module>

    <!-- naming -->
    <!-- disabling until decide on regex that's flexible enough for math names
    <module name="MemberName">
      <property name="format" value="&namingRegEx;" />
      <message key="name.invalidPattern" value="Member name ''{0}'' must match pattern ''{1}''." />
    </module>
    <module name="ParameterName">
      <property name="format" value="&namingRegEx;" />
      <message key="name.invalidPattern" value="Parameter name ''{0}'' must match pattern ''{1}''." />
    </module>
    <module name="LocalVariableName">
      <property name="format" value="&namingRegEx;" />
      <message key="name.invalidPattern" value="Local variable name ''{0}'' must match pattern ''{1}''." />
    </module>
    <module name="MethodName">
      <property name="format" value="&namingRegEx;" />
      <message key="name.invalidPattern" value="Method name ''{0}'' must match pattern ''{1}''." />
    </module>-->
  </module>
</module>