I tried to modify xsl files to change metadata edition forms. For example I tried to change element language (second element from the top in Advanced view -> Metadata ) from conditional to mandatory. The problem is that I don’t know the structure of the files and connections between them, and I don’t know how it’s working. I think if I would know how to change this one I can do rest by myself. Do You have some documentation of xsl files in geonetwork? Can You tell me which files are responsible for edition forms?