Squawk Ident
Another squawk ident question.
Flying out of London City, Tower hand us over to Thames who want a squawk ident.
I can understand this is to identify us.
We then go to London who often, but not always, ask to squawk ident.
Why do London need it? They are in the same control room as Thames, I think, and Thames have already identified us.
When we go to other units later in the flight e.g. Scottish, Amsterdam etc they do not ask to squawk.