How do the occult tags work?

When making CAS content, if you disallow an item for mermaids, for instance, does this disallow the item for only the mermaid form or for a sim who is a mermaid but in human form?

There are items I'd like to restrict for the alternate forms (especially for werewolves and mermaids since there's a lot of distortion for those with some items) but not for their human forms.

Is this how the tags work, and if not, is there another way to restrict items to/from the alternate forms?