XmDragStart(3) on Linux
The text 0438a17b7088, as Debian 13 (Trixie), Debian 12 (Bookworm), Debian 11 (Bullseye), Debian 10 (Buster), Debian 9 (Stretch), Debian 8 (Jessie) shipped it.
A Drag and Drop function that initiates a drag and drop transaction "XmDragStart" "Drag and Drop functions" "XmDragStart"