ptp4l(8) on Linux
The text 2286a49daaec, as Debian 9 (Stretch) shipped it.
PTP Boundary/Ordinary Clock
Flags it lists
-
-2 -
-4 -
-6 -
-A -
-E -
-H -
-L -
-P -
-S -
-h -
-m -
-q -
-s -
-v