CC reserving pitches

During a recent short (3 night) break we had to use a grass pitch as the hard-standing pitches were being reserved for other members who were, when they arrived, staying on site for 1 to 2 weeks.

I was of the belief that all pitches are on a first come, first served basis. Can anybody confirm one way or the other please?

What made it worse was there was at least one empty hard-standing pitch every night we were there!! Don't know if this was due to no-shows, early departures or what.