Adding One-Time Events to Unusual Places

I've run into this situation several times now and am wondering what is the best way to handle it.
There are well-known author book signings/events at locations that are not book-related at all. For example, at a community room at a casino, at a Canine Companions for Independence campus. I don't really want to put the venues into the system, even marked as "other," because they are so off-the-wall and likely to never have another event.
Should I enter them temporarily and then delete them after the event, or what? I've been not entering them or the event at all, but that doesn't seem right either.

You could enter it as a Festival if you're really that worried, but truthfully, that's what "Other" is for.

Thanks. I've gone ahead and entered one, as "other" of course, put in the description that it is a temporary listing for a specific event, and I'll just delete it afterwards.

Another solution is if it's sponsored by an organization that does a lot of reading-related events. Then you can enter the name and address of the organization, then enter the events on that page with their proper address.