Hi @stiegjo, JCR query is not supporting regular expression. Some operators supports wild cards e.g.
- LIKE supports: % and _
- CONTAINS supports: * and OR
In your case I would simply use query to get all users and as a next step do the filtering on Java level.
You can also try to build a query that will check if specific (unwanted/special) char is included in givenName or familyName - so the other way around comparing to your current strategy. But I can image that this kind of query could be complex and maybe it will not give you the expected result.