ref: 6b8eb26a267808c5ebcb6ec38f0b4806c54c5d6f dir: /sys/src/cmd/htmlroff/t15.c/
#include "a.h" /* * 15. Output line numbering. */ void t15init(void) { addreq(L("nm"), r_warn, -1); addreq(L("nn"), r_warn, -1); }