isotptun(1) on Linux
The text cdce48b97187, as Debian 12 (Bookworm), Debian 11 (Bullseye) shipped it.
manual page for isotptun 2020.11.0-1
Flags it lists
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-D -
-L -
-P -
-b -
-d -
-h -
-m -
-n -
-p -
-s -
-v -
-w -
-x