openrocket/config/checkstyle/checkstyle.xml

<?xml version="1.0"?>
<!DOCTYPE module PUBLIC
        "-//Checkstyle//DTD Checkstyle Configuration 1.3//EN"
        "https://checkstyle.org/dtds/configuration_1_3.dtd">

<module name="Checker">
    <module name="SuppressWarningsFilter"/>

    <property name="charset" value="UTF-8"/>

    <property name="severity" value="warning"/>

    <property name="fileExtensions" value="java"/>
    <!-- Excludes all 'module-info.java' files              -->
    <!-- See https://checkstyle.org/config_filefilters.html -->
    <module name="BeforeExecutionExclusionFileFilter">
        <property name="fileNamePattern" value="module\-info\.java$"/>
    </module>
    <!-- https://checkstyle.org/config_filters.html#SuppressionFilter -->
    <module name="SuppressionFilter">
        <property name="file" value="${org.checkstyle.google.suppressionfilter.config}"
                  default="checkstyle-suppressions.xml" />
        <property name="optional" value="true"/>
    </module>

    <!-- Checks for whitespace                               -->
    <!-- See http://checkstyle.org/config_whitespace.html -->
<!--    <module name="FileTabCharacter">-->
<!--        <property name="eachLine" value="true"/>-->
<!--    </module>-->

<!--    <module name="LineLength">-->
<!--        <property name="fileExtensions" value="java"/>-->
<!--        <property name="max" value="100"/>-->
<!--        <property name="ignorePattern" value="^package.*|^import.*|a href|href|http://|https://|ftp://"/>-->
<!--    </module>-->

    <module name="TreeWalker">
        <module name="Regexp">
            <property name="format" value="(FIXME|TODO:.*CRITICAL)"/>
            <property name="illegalPattern" value="true"/>
            <property name="message"
                      value="CRITICAL TODOs exist in project."/>
        </module>
        <module name="Regexp">
            <property name="format" value="\P{ASCII}"/>
            <property name="illegalPattern" value="true"/>
            <property name="message"
                      value="Non-ASCII characters exist in project."/>
        </module>
        <module name="IllegalTokenText">
            <property name="tokens" value="STRING_LITERAL, CHAR_LITERAL"/>
            <property name="format"
                      value="\\u00(09|0(a|A)|0(c|C)|0(d|D)|22|27|5(C|c))|\\(0(10|11|12|14|15|42|47)|134)"/>
            <property name="message"
                      value="Consider using special escape sequence instead of octal value or Unicode escaped value."/>
        </module>
    </module>
</module>