XmActivateWMProtocol(3) on Linux
The text 3be08e2c8824, as Debian 13 (Trixie), Debian 12 (Bookworm), Debian 11 (Bullseye), Debian 10 (Buster), Debian 9 (Stretch), Debian 8 (Jessie) shipped it.
A VendorShell convenience interface that activates a protocol "XmActivateWMProtocol" "VendorShell functions" "XmActivateWMProtocol" "protocols"