I'm with Lew Ton here. The ADT was what the slot was known as prior to CFMU 3 ops. The CTOT is just the new name for it and I agree, they are all just slots !
If you're having difficulty sleeping try
http://www.ais.org.uk/uk_aip/pdf/enr/20109.pdf for the UK AIP gospel (produced by London FMP I think) and / or
http://www.cfmu.eurocontrol.be/doc/c...MANUAL_6_0.pdf for the entire ATFM users manual for the word from the horse's mouth !
RT