“Eligibility” refers to the ability of players to touch legal forward passes, only, before the ball is touched by any player of Team B, or an official, anywhere on the field. Backs and ends (both as defined by rule) wearing numbers OTHER than 50-79 are eligible to touch a legal forward pass, before it is touched by Team B or an official. All Team B players are always eligible to touch a forward pass.
No ineligible player may touch a legal forward pass, anywhere on the field, before it is touched by Team B or an official.