<P> Once a forward pass is in the air it is a loose ball and thus any eligible receiver--all defensive players are eligible receivers--may try to catch it . When a defensive player catches a forward pass it is an interception and his team gains possession of the ball . Some actions that are defined as pass interference may be overlooked if the defender is attempting to catch or bat the ball rather than focusing on the receiver . </P> <P> The intended receiver may find himself a defender if a defensive player has a better chance to catch a forward pass . If an offensive player commits pass interference against a defensive player attempting to intercept a forward pass it is offensive pass interference . </P> <P> Rules for pass interference differ between American and Canadian football: </P> <Ul> <Li> Pass interference rules in American high school and college football clearly cover only forward passes that travel beyond the neutral zone . In the NFL, the official rule is that "there can be no pass interference at or behind the line of scrimmage". In Canadian football, pass interference rules are applied throughout the field of play . This leads to differences in the application of the rule on screen passes in which the intended receiver is behind the line of scrimmage: <Ul> <Li> A defender who makes contact with an intended receiver behind the line of scrimmage cannot be called for pass interference at any level of American football, although he may still be guilty of a different foul . The NFL is specific about which foul could be called in that situation, stating that "defensive actions (behind the line of scrimmage) such as tackling a receiver can still result in a 5 - yard penalty for defensive holding, if accepted ." In the same situation in Canadian football, the defender can be called for pass interference if his contact is deemed illegal . </Li> <Li> Offensive pass interference cannot be called behind the line of scrimmage in American football . In Canadian football, although the pass interference rule applies, offensive players are explicitly allowed to interfere with a defender attempting to intercept a screen pass (within certain limitations). </Li> </Ul> </Li> <Li> If the pass is deemed to be "uncatchable", pass interference rules do not apply in American college football or the NFL, and starting with the 2010 season they do not apply in Canada . This rule does not apply in American high school football . </Li> </Ul>

When did the nfl change the pass interference rule