Question about NFL rule

[butkus]

What I presented you with was all I could find in the whole NFL Rulebook concerning goal lines. I went through 200 pages, and that is all the book said about touchdowns and the goal line. There was NOT ONE mention of a "goal line extended" the only mention was of the plane and that players must be inbounds while legally possessing the ball. There is the mention that the ball MUST be "on, over or behind the goal line" in order to be a TD.