RE_NO_BK_VBAR     156 lib/regex.h    # define RE_NO_BK_VBAR (RE_NO_BK_REFS << 1)
RE_NO_BK_VBAR     126 test/manual/etags/c-src/emacs/src/regex.h #define RE_NO_BK_VBAR (RE_NO_BK_REFS << 1)