The referee may be assisted by VAR only in relation to five categories: goal/no goal, penalty/no penalty, red card, mistaken identity, and a clearly incorrectly awarded corner kick. The last of these is a competition option, so it is not available everywhere. The protocol also governs how interventions are carried out, not just whether they happen at all, and it sets out what does and does not follow when the technology itself fails. Law 5 makes the use of technology something a competition may adopt, not something the Laws require.