I see diamonds used as a major symbol, or just nothing, eg. C = c major
triad, if there is added 7th, the symbol will usually say.
Sometimes you see diminished written like this Co or Co7,
b5 chords sometimes are witten as a 0 with a / through it, some people call
these half diminished chords.
+ usually means augmented or #5 within that chord.
There's more but those are usual problem spots.
Mark A Corradetti
NASHVILLE