Sideline Warning?

[Warrenkicker]

I'll go with 9-8-3 of course being the main rule covering sideline interference. It lists the penalties include the first offense being a warning. Now we can't have a penalty with out a foul and it states that the warning is a penalty. So to have a foul we must have a flag to indicate that a foul was committed. So I say that all sideline warnings must be flagged or else they did not foul.