Prohormone structure confusion

Does anyone have a quick reference guide to all the prohormones out now? I am trying to decipher some things like when Bill said dermal DHEA converts to androstandiol (which #'s? 4 or 5 etc) and this was an immune stimulant. Then we have 4 and 5 diols and now 1-AD…and Llewellyn etc are selling adroSTANAdiones and diols (again which #'s? 1-4 something?)…and Kilosports has 5A-A—TRIOLS…

So again why the difference in stene/stane and diol/triol and the multiple numberings?
Thanks