If the crossbar
breaks during a match played under the rules of a competition and there
are no available means of repairing or replacing it, should the match be
abandoned?
Yes. The crossbar is a part of the goal and must always be in place.
Is it necessary
for flags to be placed at the half-way line?
No. Such flags are optional.
Is it
permissible to mark the field of play with broken lines?
No. Law 1 does not allow broken lines.
A goalkeeper or
another player draws unauthorised marks on the field of play with his
foot. What action does the referee take?
If the referee notices this before the match starts the offending player
is cautioned for unsporting behaviour.
If the referee
notices this being done during the match he cautions the offending
player for unsporting behaviour when the ball next goes out of play.