Reference

bmtoa(1x) on Linux

The text b3fe6bec3e00, as Debian 2.2 (Potato), Debian 2.1 (Slink), Debian 2.0 (Hamm), Debian 1.3 (Bo) shipped it.

bitmap editor and converter utilities for the X Window System

Flags it lists

bmtoa(1x) on Linux now