The shirt reads: a branching diagram: YOU and ALL combine into YA’LL; ARE NOT and AIN’T combine; and the two branches meet at the bottom in YAIN’T.
It is drawn in white handwriting with plain arrows, like something worked out on a whiteboard.
It is a genuine derivation of a word that people really do say, set out as a linguistic tree. The working is correct even if the result is not in any dictionary.
For the South, for linguists, and for anyone who has used the word and never seen it justified before.
