RE_NO_BK_PARENS   148 lib/regex.h    # define RE_NO_BK_PARENS (RE_NO_BK_BRACES << 1)
RE_NO_BK_PARENS   118 test/manual/etags/c-src/emacs/src/regex.h #define RE_NO_BK_PARENS (RE_NO_BK_BRACES << 1)