Denti
The "ident" can be for a number of different reasons.....besides the confirmation of aircraft identity and ensuring that the correct SSR code correlates to the correct flight. On my sectors the "ident" will trigger the code-callsign conversion [if not automatically done] and starts to track the aircraft.....depending on the particular bit of airspace it can change the "label" from a background grey colour to a foreground green colour.
Occassionally an aircraft might display a wrong code [misheard or selection error or redundant pairing or similar] and this may cause a wrong label to be displayed and/or activate the flight plan for the wrong flight.