ref: 51a9ff535bf6db2539af3f94ae15533ae7cbaabe 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); }