In macro instruction operand values, there must be an equal number of left and right parentheses. They must be paired, that is, each left parenthesis needs a following right parenthesis at the same level of nesting. An unpaired (single) left or right parenthesis can appear only in a quoted string.

(PAIRED-PARENTHESES)
()
(A(B)C)D(E)
(IN'('STRING)