What happened to these 2-letter .org's?

[alia]

ac.org
fs.org
mw.org

Try any registrar except Go Daddy, and you'll find they are all available, but you can't really register them, anyone knows why?

 

[Mr Webname]

The new registry (www.pir.org) has decided that all expiring 2-letter/character .orgs will not be renewed. It appears that very soon the same fate will befall 2-letter/character .com and .net - you may have noticed that Snapnames no longer offer 2-letter/character snaps..

 

[alia]

Thanks, so that's why Go Daddy won't search any 2-letter.