Man pages matching name probe::netfilter.ip.forward in section 3stap:

probe::netfilter.ip.forward.3stap.en	debian 10 / systemtap-doc
probe::netfilter.ip.forward.3stap.en	debian 11 / systemtap-doc
probe::netfilter.ip.forward.3stap.en	debian 12 / systemtap-doc