ESC_REF           588 ext/pcre/pcrelib/pcre_compile.c     c = -(ESC_REF + c);
ESC_REF           619 ext/pcre/pcrelib/pcre_compile.c         c = -(ESC_REF + c);
ESC_REF          5106 ext/pcre/pcrelib/pcre_compile.c       if (-c >= ESC_REF)
ESC_REF          5108 ext/pcre/pcrelib/pcre_compile.c         recno = -c - ESC_REF;