In the definitions of the R & A Rules of Golf it states that a tee "must not be longer than 4 inches (101.6 mm)" and Rule 11 states "If a player makes a stroke at a ball on a non-conforming tee, or at a ball teed in a manner not permitted by this Rule, he is disqualified."
I and others, sometimes join two tees together by inserting one inside the other to gain extra height for teeing off. If the combined length of the two tees is less than 4 inches does this arrangement still qualify as a conforming tee?