What does +3v3a mean in a schematic

What does "3v3a" mean in a schematic, I see it next to a connector like it comes out of the rectifier bridge then the smoothing caps etc then it says +3v3a. I also see it in - else where, and I see +5vd or +5VV or -5VV ...

What does that mean exactly.

Thanks in advance.
Cool.
Srinath.