I had to ask permission but that was 33 years ago, i think it is just a courtesy thing these days, with all the liberal attitudes of today it is not as if it is going to matter is it , but i suppose it is better to be safe than sorry , he/ she would not want to spoil their chances of promotion for the sake of a two minute visit to the commanding officers office, they do tend to hold a grudge , or at least they did when i was in. he/she should ask their company/troop/battery/platoon officer who should be able to tell them straight away.