Is there any notation or abbreviated phrase meaning "this is provisional"?

I want to write on my timetable that an event will take place at "Building X, but this is provisional as it is subject to change and it may happen somewhere else." Is there any kind of notation or abbreviated phrase in English, Latin or Greek etc. that denotes being provisional? I'm not sure "etc." carries that sense across.

As Frank commented on Robusto's answer, the most common abbreviation for this I'd expect would be

TBC (to be confirmed).

You can use TBA in a slightly different context. I'd find it plausible to see, for example:

Lecture A1. Topic: Frogs. Location: Lecture Hall X
Lecture A2. Topic: Fish. Location: Lecture Hall Y (TBC)
Lecture A3. Topic: Flies. Location: TBA

That is, "TBA" implies ''nothing has yet been announced at all''; "TBC" implies ''something has been announced but not yet finalised''.

Usually a parenthetical TBD (to be discussed or to be determined) or TBA (to be announced) would suffice.

edit

I'm including @Frank's "TBC" even though I've seldom seen it. This answer should probably encompass all the TB* variations. No doubt there are others as well.

For those who are well versed in Latin, "ad interim" is a good fit.

• "ad interim" (adverb) for the intervening time, temporarily TFD - "an ad interim government until the new constitution goes into effect"

"provisory" or "provisional" alone also convey the meaning you're looking for.

• provisory (adj) - another word for provisional
• provisional (adj) - provided or serving only for the time being. TFD

Edit: credit to Josh61, "ad interim" can be abreviated to "ad int".