Rb26 Short Vs Long Blocks

[aphid]

hey all.

i've seen this description come up time and time again, and i thought that all rb26 blocks geometrically were the same, so what does it mean exactly when one refers to an rb26 block as being either long or short? i've done a bit of a search but couldn't come up with anything useful..

cheers,

mark.

[The Dan]

short means just the block

long means including head etc.