Section Commander n. Nasty hard arsed Corporal that commands the Section.
In the infantry the role of the section is to deliver the Section Commander onto the enemy so that he can get amongst them and cause havoc and kill "Like what they pay you for" (Sgt Maxfield, Zulu). Section Commanders should be kept in locked boxes marked "To be used only in times of War" but sadly can't.
A section is usually commanded by a Corporal, with a Lance Corporal as their Second in Command (2IC). It consists additionally of typically: 2 LSW's, 2 LMG's, Radio Operator, and 2 UGL's. Leaving only the section commander and 2IC able to fix swords.