I know the structure of the rules in XML is not particularly complicated, but is there a DTD? Not being lazy, just don't want to miss anything.
The rule matches:
The rules:https://github.com/languagetool-org/languagetool/blob/master/languagetool-core/src/main/resources/org/languagetool/rules/rules.xsd and
Thanks Daniel, I'll have a look at them in the next few days!