otfinfo gives some data - at least it's quick:
Code:
[me@home ~]otfinfo -f IMFeGPrm29C.otf
aalt Access All Alternates
calt Contextual Alternates
dlig Discretionary Ligatures
hist Historical Forms
kern Kerning
liga Standard Ligatures
salt Stylistic Alternates
smcp Small Capitals
ss01 Stylistic Set 1
ss02 Stylistic Set 2
ss03 Stylistic Set 3
ss04 Stylistic Set 4