When to raise the offside flag

[TussAgee11]

I'm not a soccer official, but have played and do know some stuff.

In international play, the ruling on this involves the term passive offsides. In other words, if he's out of the play, don't raise the flag. Let play continue. This has been a recent change implemented by FIFA: it used to be that once a player was off, raise it, and blow it (assuming it was not a shot).

When I played, it was raise it as soon as the ball was moved ahead. I'm not sure if they changed this as well.