Think of #afm as a filter on the wider porn caption caption archive: same submission pool, but slimmed down to the exact register you searched for.
The page pulls in afm-tagged captions, plus caption GIFs where afm is a secondary tag, plus roleplay posts whose title text overlaps with the afm keyword — three sources into one feed.
Because #afm is tag-locked, the recommendations under each post also stay in the same lane, which means fewer 'that wasn't what I wanted' clicks and more time on the actual fantasy.
As more creators publish under #afm, this page rebuilds itself daily with fresh title, alt, caption and tag combinations — meaning what you saw yesterday is not what you'll see tomorrow.