ref: 9ef4ba83f62761b517db23a16e2f61e5861aae23
dir: /sys/lib/troff/font/devutf/charlib/rc/
/build_RC { pop size 4 div /side exch def currentpoint newpath moveto 0 side 1.5 mul rmoveto 0 side rlineto side 2.5 mul 0 rlineto 0 side neg rlineto closepath fill } def