I don't have any plans to add an annex - but the orbits are generally decoded as such:
L---: Low
M---: Medium
G---: Geosynchronous
H---: High
-T--: Tropical (0-30 degrees inclination on Earth)
-I--: Inclined (30-60 degrees inclination on Earth, 45-90 degrees around the Moon)
-E--: Exotic/Eccentric (mostly represents Tundra and Molniya orbits)
-P--: Polar (60-90+ degrees inclination on Earth)
--E-: Earth
--L-: Lunar
So, LTEO is Low Tropical Earth Orbit, for example. The only exception is LTO, being Lunar Transfer Orbit. Hope that helps!