groff_man(7) on Linux
The text d321ccf3a893, as Debian 10 (Buster) shipped it.
GNU roff macro package for formatting man pages
Flags it lists
-
-rC1 -
-rD1 -
-rFT -
-rHY -
-rIN -
-rLL -
-rLT -
-rP -
-rS -
-rSN -
-rX -
-rcR