XmTabListCopy(3) on Linux
The text dff6d7fbe2c7, as Debian 13 (Trixie), Debian 12 (Bookworm), Debian 11 (Bullseye), Debian 10 (Buster), Debian 9 (Stretch), Debian 8 (Jessie) shipped it.
A convenience function that creates a new tab list from an existing list "XmTabListCopy"