Well if you don't supply the Domain it typically will still find it, but it will take longer even if it is only milli-seconds. Same with batch etc.. .COM,.EXE,.BAT in that order are still located by a Windows system in that order when not specified.

KiXtart will lookup the data and find it, but if as an example you had 5 Domains (it could look in all 5 Domains for the group) but would be slower and would work on the first one found which typically would be from the Domain you logged onto, but not necessarilly the one you wanted.

Just saying. Specifying extensions, and prefacing when required will be quicker, not that it won't work. By being quicker we're not talking about speeds that are noticeable to the human eye.