--edit-key Information

[Gary Hanley]

Hello,

Try as I might I can't seem to find any solid information regarding 
some information under --edit-key. Consider this slightly redacted 
example:

pub 1024D/92323698 : 2009-12-11 expires: 2011-12-11 usage: SCA
                      trust: ultimate validity: ultimate
sub 4096g/746E2A67 : 2009-12-11 expires: 2011-12-11 usage: E

Where do I find information about the "D" in "1024D" and the "g" in 
"4096g"? What are the other potential values?

And although the answer may be obvious or intuitive, is there a source 
of information that describes the values of the "usage:" flags?

Thanks for any help you can give me.

-- Gary