wierd part number suffixes at mouser??? anyone help?

[Brian Marshall]

browsing through mouser recently.

I have noticed more and more suffixes for transistors popping up.

i normally order 2n5457 farichild jfets
mouser number 512-2n5457

now all these other ones are popping up like
512-2n5457 d26z
512-2n5457 d27z
512-2n5457 d74z
512-2n5457 Q

now when i order 512-2n5457, sometimes they come on tape, and sometimes they come in a bag, but that's neither here nor there.  anyone know what any of those suffixes mean, or know where i can find out.  My guess is they dont mean anything, and have something to do with packaging.  BTW  they are all TO-92 type