I program Fadal mills. And they use the G28 different than the Fanuc format. Absoute mode and the code by itself.
N1G28 (typically)
We also have one Haas mill which follows the Fanuc format. But since the code G91G28X0Y0Z0 sends the machine spindle to the far right hand machine home position, I do not like to use it.
Instead I use the machine coordinate system command G53.
(first program blocks)
G90G53Z0
G53X-15.Y0 (machine has a 30 inch X axis travel)
(last program blocks)
G53X-15.Y0
G0G90G40G80T1M6
M30