While the token "next_CE_1" is good for the reference element "self+1", "last_CE_1" is not as good for "self-1", so I propose "prev_CE_1", for quite obvious reasons

I think that this token has never been used in any configuration file yet (and hardly will be used in the future), so this change shouldn't break anything.
Hey, wait a moment, those reference elements' tokens shouldn't even be displayed!
Uh, just got the answer on my own: one could wish to customize the graphical buttons for them, so will use their tokens, okay.
Seen your votes, and counted them a bit (Yes: 4, No: 0) seems that the token should be renamed.