position isomerism

18 LETTERS · STARTS WITH P

position isomerism is a valid 18-letter word worth 23 points in Scrabble and 27 points in Words with Friends.

SCRABBLE WORDS WITH FRIENDS

P3O1S1I1T1I1O1N1I1S1O1M3E1R1I1S1M3

3 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 0 + 1 + 1 + 1 + 3 + 1 + 1 + 1 + 1 + 3 =23 PTS

DOUBLE WORD → 46TRIPLE WORD → 69

MEANING

What does position isomerism mean?