Industry standard as in everyone uses it in almost every engine and hence, its 'standard'.
That's pretty funny. I'd term that "marking standard" or maybe "user standard" though
. I haven't bought an OS plug in years. Actually, I take that back, I have a spare OS F plug around somewhere. I use them in my 4-bangers. But I use K&B plugs in my 2-strokes. To each his own.
OS plugs are probibly the most common plugs in use though.