Depth Gauges/Misc ?s

[lumberinspector]

1.) I have read about the "constant method"...have also read it isn't a good practice?

True of False?

2.) What is the proper way to file them?

3.) Are the basic filing angles the same for ALL kinds of saw chain?

I have a few of the file/guide combos from Oregon but I run Stihl chian...does it matter?

Thanks in advance guys for all your help.