Answer: Dear Me, As explained here , you must add the override=“true” parameter into your schema description. <schema override="true" name="group" src="directoryschema/group.xsd"/> You must have a message in your log that says your contribution is ...

Answer: For the user field, you just have to create the schema that stores a string (if you want attach only one user) or a string list (for several). After you can use the same suggestion box widget we use for Right Management. For two next fields, in fact ...

Answer: All of those are XML files, so you can use any XML editor to create them. Nuxeo Studio has a graphical user interface to create them, but it's not open source.