(
Means Start Parameter, Command or Subpattern (in Regexp)
Left parentheses "(" introduces the size of a file, a window for string matches, and is always matched by an ending ")".
/list "string" (smart upshift)Left parentheses "(" can be used to enclose commands which include commas or semicolons that might be confused with delimiters. Qedit considers everything between the left and right parentheses as one command. This is mostly useful when multiple commands appear on one line.
/F "test";(listspf o ;seleq=[owner=mgr.acct]);Li */*+5Left parentheses "(" are used to divide regular expressions into smaller portions called subpatterns. Left parentheses identify the start of a subpattern.
/List "x(abc)z" {subpattern starts with "a"}