Checked that one as regards to officers.(UK) We got married in 1973 and didn't have to ask .My husband says it changed with the introduction of the military salary in 1970. Before that the single officers would have lived in the mess, got their board and lodging paid before they were paid. After that they had to pay their mess bill, their batman's tip and the rest of the money was disposable. Married officers who had to be over 25 got a marriage allowance and entitlement to a quarter
Even though there was nothing to stop us in 1973, it wasn't easy . Wives hadn't traditionally worked, and expenses that were fine for a single officer were high for two.I taught which was just about acceptable, some jobs weren't acceptable
.I found this from 1964, it's an army document which confirms that permission had to be sought from the CO before getting married http://www.1rtr.net/customs.htm