I usually assume that a chord request is either for:

... a suitable accompaniment, but for a song that's not easily figured out by ear. To my old-timey/bluegrass ear, I still have trouble coming up with suitable accompaniment for Celtic fiddle tunes.

... a "signature" chord or two. Sometimes a song is brought to mind by, not just a chord, but a particular way to play a chord -- maybe a simple inversion of the chord. For instance, try to play a Travis song with only the first position E chord. You could sing along, but it'd never sound "right".

... some chord progressions regularly confuse beginning to intermediate players. For instance, one of the most often confusing (to the beginner) progressions is the major to minor that, rather than going to the relative minor (like G to Em), is actually going to the minor of the chord (G to Gm). For some reason, though the beginner can hear the change to minor, they can't seem to find which minor.

When a chord progression is confusing, one can either go through all the chords in their chord book, or they can post here. We'll happily answer. It beats all hell out of yet another political arguement.