independent media

I'm not sure if this is an appropriate "Radical Reference" question but I'll give it a try. I'm currently cataloguing a zine collection for the Anchor Archive Zine Library in Halifax. Each zine record has a broad category plus multiple subject terms/keywords describing the content. Assigning subject terms to each zine is challenging, and I think it would be a lot easier if I had a thesaurus of subject terms to refer to, such as Library of Congress Subject Headings but for collections of alternative media. I've tried looking up online catalogues for other zine libraries and alternative bookstores for lists of subject headings, but I haven't found anything yet. Most don't seem to index their content by subject, which is probably smart considering how time consuming it is. I've also posted a message on the Zine Librarians Yahoo Group listserv but I didn't get many responses. Do you have any other suggestions of where I could find alternative thesauri, for alternative media in general or in specific subject areas, such as feminism and anarchism? I would really appreciate any help you can give me. Thanks!