Folks:
I'm embarking on writing some modules that need to read/write AFNI files. I've found docs on most format-related items, and have corresponding code working OK.

However, I need to know what rules AFNI has for file names. Obviously there's the ".HEAD" and ".BRIK" extension, but beyond that what does AFNI expect...
a) the form of the file name (seems like the +something part at the end is significatnt
b) what implications or links there to file names in the header file. (eg: does require only that head and brik filenames match, or must the file names match those mentioned in the header file)
c) File Id -- I'll probably have to read the C source on this, but it would help to know whether this is an arbitrary string, or is it calculated from the volume or somesuch.

Perhaps there's a doc on this that I've missed?

Any comments appreciated, thanks,

Graham