I wasn't me that said it, but I do think you understand it correctly now.Makes perfect sense. I think I was slightly confused. Read what you were saying originally out of context I think and was interpreting it in that you meant " a bird with a crest genetically cannot also express muff/beard" BUT (LOL) that isn't what you were saying at all lol. I think it scared me and caught my attention because I'm considering an EE project that would make a bird that has a nice fluffy crest AND muffs and beards. Lol. So that was what prompted me asking. I was thinking maybe there was some kind of genetic conflict with those traits that I wasn't aware of. Lol. But you were simply saying with the breeds in the birds background it would not also have those traits. Thanks for the info and your patience and kindness! Much appreciated
Chickens definitely can have a crest and also muff/beard. That combination is found in Sultan chickens and in Araucanas in some countries (including Australia and England, I believe.) Silkies and Polish often have muff/beard to go with their crests too.