differences between starter codes

[Jasikasisback]

hi again..

so I was wondering if anyone knows the difference between the starter codes.

the one on my car is 020 911 023M.

I have found a page that says that this starter has been superseeded by ones with F, FX, and N instead of the M....

Now I am not sure if all of these starters are the same, will fit the same gearboxes or is it a case that the one version will work with some but not the others....anyone have any idea...
I don't want to damage my car... but would have more options when at the scrapyard..

[Jasikasisback]

come on guys someone must know....mine is automatic 9 tooth so i don't know which ones are compatible other than the M version that is on my car.....