The spelling errors in the six words or phrases below can be summarized by a familiar phrase. Can you determine what it is?

INSIGNICANT
GT CERTICATE
TEN COMMMENTS
CY BAR
TERFINGERS
DEANTE

Answer:

"NO IFS, ANDS, OR BUTS"

insignIFicant
gIFt certIFicate
ten commANDments
cANDy bar
BUTterfingers
deBUTante 

Credit: NY Times Crossword - Nov. 10, 1985
John Greenman
NO IFS, ANDS, OR BUTS