Coaches on field- live ball foul?

[ljudge]

Technically speaking, "letter-of-the-law" enforcement on this is always 15 yards. The warning, followed by a 5-yarder, followed by 15-yarders is when a coach is outside the team box, but not on field. e.g.: standing on the 20 yard line beyond the sideline

I have typically given warnings as well but if we all enforced it the way the fed wants us to it would probably put an end to coaches encroaching on the field.