To me "X" indicates a breeding, as in super pastel X cinnamon read as “super pastel cross cinnamon”. Perhaps not how it was meant above but just for the record you can't produce an animal that is both a super pastel and a cinnamon by breeding a super pastel to a cinnamon. This is because the super pastel can only give one copy of the gene at the pastel locus (or one copy of any gene for that mater). Being a super pastel just means that it gives the pastel mutant version of that gene to all of it's offspring but still only one copy to each. Not sure what is the right way to denote a combo of different genes in the same animal. Sometimes I use the "+" symbol like super pastel + cinnamon to indicate one animal that is both (I've not even tried to keep up with the names after pewter). But I know on Kingsnake the + symbol doesn't post for some reason. I did see someone recommend "\\" for combos of two different alleles of the same gene once, like lesser\\phantom for the karma combo. Don't know if that applies to combos of different genes and I've also seen forums strip a pair like \\ down to just one \.
Black Pastel X Pastel = Black Pewter (Pastel Black Pastel)
Black Pewter X Pastel = Silver Streak (Super Pastel Black Pastel)
Cinnamon X Pastel = Pewter (Pastel Cinny)
Pewter X Pastel = Sterling (Super Pastel Cinny)
Black Pewter X Pewter = Silver Bullet. Incorrect. :
Black Pewter x Black Pastel = Silver Bullet (Pastel Super Black Pastel)
Pewter x Cinnamon = Silver Bullet (Pastel Super Cinny)
Black Pastel X Black Pastel = Super Black Pastel
Cinnamon X Cinnamon = Super Cinnamon
I wonder... Silver Streak X Sterling..
A Silver Streak (Super Pastel Black Pastel) crossed with a Sterling (Super Pastel Cinnamon) gives each egg 25% chance of being a Super Pastel Black Pastel Cinny (a form of a Super Pewter since Black Pastel and Cinnamon are allelic), 25% chance of being a Super Pastel Black Pastel (Silver Streak), 25% chance of being a Super Pastel Cinny (Sterling), and 25% chance of being a Super Pastel.