Im gonna take a stab at figgurin out some type of code! (dish pro only!)
1xy-4xy = Basic receivers
5xy-9xy = Advanced Receivers
now for the XY, seems like the Y is for embeded smart card, and X is for the # of tuners (yeah, i know it dont fit the bill on the 510's but meh!)
Now, it sorta works, as your
111 = basic box + smartcard
301 = basic, no smartcard
311 = basic + smart card
211 = entry level HD (as its more commonplace) 1 tuner, and yes on embeded smart card, same w/ 411 etc
411 = hd + smartcard
501 = advanced box, no smart card
508 = advanced box, no smart card
510 = advanced box, no smart card
622 = your Advanced box, 2 tuners, with a embeded smart card (0 = no, 1+ = yes)
625/522(the 522 fits it) = your Advanced box, 2 tuners, with a embeded smart card (0 = no, 1+ = yes)
721 = 2 tuners, exception!
921 = 2 tuners, exception!
942 = tuners (exempt) embeded smart card
942+= tuners (exempt) embeded smart card
Now, it dont make much sense, or even work, but now im confused!\
211 = entry level HD (as its more commonplace) 1 tuner, and yes on embeded smart card, same w/ 411 etc
411 = hd + smartcard
(but really , those are one in the same, sorta)
622 = your Advanced box, to eventually replace the 942 id bet, 2 tuners, with a embeded smart card
942+= tuners (exempt) embeded smart card
But, you see, the 'new' mpeg 4 boxes, makes it alot easier on E to figure out what is going on , so it would only be 2 'new' mpeg 4 boxes to support, your SD/HD basic box, your SD DVR, and your HD DVR!
But Edit, it just seems like there trying to 'standardize' there model receiver #'s, though they could call them the A-F series, and Id be happy, just need HD!!