I've already got the information from my company, but I want to know more
You know, many airports have their own specific features that are not described in the manuals...
For example if you ever fly to Vnukovo (UUWW) airport you may be very surprised being asked by ATC to hold nearby for unknown period without any explanations... It's just because our mr. president uses this airport very often and his SLOTs are secret and are not published in NOTAMs due to safety reasons...