On the average stapler, the bottom plate that actually shapes the staple (bends the prongs of staple in to close it off), is mounted on a swivel.
This allows you to rotate it around and gain access to another shape that bends the prongs outward.
What the hell is the purpose for this other plate? Why would anyone want the prongs to be bent out so that they snag on everything?
Those are intended for stapling together papers you know will need to be unstapled shortly – the outwardly bent kind can simply pulled out lengthwise with a little effort and very little damage to the papers.
In essence they serve the purpose of a paperclip, but are less likely to catch on other papers and be pulled free by accident.
To staple something temporarily. You can remove those very easily.
Ah, I see. Never thought of that.
The Stapler Database has all your stapler answers.
Of course* there’s a stapler database.
Sometimes the Web still amazes me.
RR