conventional symbol

19 LETTERS · STARTS WITH C

conventional symbol is a valid 19-letter word worth 30 points in Scrabble and 38 points in Words with Friends.

SCRABBLE WORDS WITH FRIENDS
C3O1N1V4E1N1T1I1O1N1A1L1S1Y4M3B3O1L1
3 + 1 + 1 + 4 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 1 + 0 + 1 + 4 + 3 + 3 + 1 + 1 =30 PTS
DOUBLE WORD → 60TRIPLE WORD → 90
MEANING

What does conventional symbol mean?

1