The unit's head is known as "Q" and was portrayed in many of the films by actor Desmond Llewelyn (2nd film to the 19th).
2. By inference, a specialised higly technical department within a much larger organisation, often staffed by geeks whose work is little understood but none the less admired and respected by other employees.
Also known as "Q Section"
"Yeah... but I'll be a little late, I have to go up to Q Branch and get them to look at my GPS, it's playing up."