Pte is a written short form of Private, the lowest rank in the British (and some Commonwealth) army. You see it before a name in lists, letters, and reports: Pte Smith. It is for writing; people usually say private, not the three letters. A private is a regular soldier, not an officer. The American army writes Pvt for the same rank. This is not private as in a private room or private information — here it is a soldier’s rank. Though actually, in Singapore and some other places you will also see Pte. Ltd. on company names, where Pte means a private company. That is a different private, and not this army use.