Is an AV's UUID stable?

Will the UUID associated with an avatar ever change? It seems to remain the same after logging off and back on again. But do the Lindens ever change them for some reason? I'm writing a script where I would like to be able to count on the fact that an avatar's UUID will always be the same.

To my knowledge barring some catastrophic loss of the entire DB (in which case there'd be worse things to worry about) an avatar's UUID doesn't change for any reason.... ever.

The UUID will most likely stay the same but there is absolutely NO guarantee that it will not change at some random point in the future.

Where exactly did u read this.. I've never seen any indication that an avatar's uuid would change.. However, when an object is rezzed.. I believe it's assigned a uuid key dynamicly.
Which means.. if you create an object, it's assigned a key, if you take it into your inventory (or the sim resets), the key changes.

While it isn't probably explicitly stated anywhere that an avatar's UUID is permanently assigned and will never change, it is implicitly accurate to say that it will never change, because doing so would cause a GREAT deal of stuff to break in SL.

So, I would say you can MOST DEFINITELY "bank on it" NEVER changing.

An avatar's ID will never change. A texture's UUID will never change. A rezzed object will change its UUID whenever it crosses a sim boundary. An inventory object's UUID will change only when it's rezzed and either attached or no-copy, and it crosses a sim boundary (e.g., attachments and vehicles).

Also, UUIDs are unique in the world, including outside SL. According to the rules, once an ID is assigned to something, it will never be assigned to anything else. Anywhere.

If LL's database ever gets so messed up that we lose UUIDs, we'll be hosed in too many ways to count. Of course, there's always the possibility for bugs to cause a UUID for a specific object or av to get messed up, but it will be exceedingly rare, and the av or object will likely be very messed up or rendered useless. That's because the UUID is the real "identity" of a thing in LL, and when something's identity is lost, all bets are off.

When writing scripts, it's safe to assume they won't change.

Yes, it will stay the same. I have had the same UUID for over a year.