I'd need to check, but isn't that somewhere's tradition? Some recollection of it being related to ad breaks in US radio shows of the 40s/50s...4T-c-4T-c-3V-c-4T-c-4T-c-3M-c-
In the UK the majority seem to go for 3T-c-3T-c-3V-c-3T-c-3T-c-3M-c... I've come across the 4T here amongst traditionalists, but mainly the 4T option in EU countries. I won't get into the 'c is silent' lazy TJs. There's also the full length 'c', which is either boring for some, or doesn't clear the floor.
The cortina needs to be sufficiently long to find another partner