Subject headings

This morning on AUTOCAT (a listserv for catalogers) someone asked about helping non-librarians assign subject headings. I just finished preparing a lecture on subject headings. Cataloging is both a science (follow the rules) and an art (application of the rules to the library and item in hand.) One can not hurry experience. In my lecture I deal with the theory and the practice of assigning subjects. I wish that I could just tell the original poster to sign up for my class.