What does the -0 in 007 indicate?

Answer 1

Presumably you are talking about the fictional spy James Bond, 007 created by Ian Fleming.

The 'double O' designation is given to those [fictional] British agents who are licensed to kill under their own decision (who would only normally be allowed to kill in self defence or under direct command of their superiors).

In the back of my mind, I seem to remember something about either the 00 prefix or the whole of the number 007 coming from the number of an office in which Ian Fleming worked.