ChibiAkumas ASM Programming Forum

What is the Xfile format used by VASM mentioned here?

https://www.chibiakumas.com/68000/helloworld.php

Is there official documentation on it?

There's some more info here

https://www.chibiakumas.com/68000/x68000.php

This was transcribed from a japanese book - I'm afraid I can't remember which, but it should be on archive org if you can read japanese