48 Hour Transit Stamp Canadian Citizen

[Lutonlhr]

I recently completed a landslide transfer from an Easyjet flight at Luton to catch an Air Canada flight back to Toronto at LHR. I wasn't scrutinized orally by the immigration officer at all, but I noticed that he only gave me 48 hours, wrote the landing card number down on the leave to enter stamp, and put an IT on the stamp.

Is that the normal procedure for transfers that involve different UK airports, or did he do something out of the ordinary?

When I have transferred overnight via Heathrow in the past, they normally just give the normal stamp, with an IT mark.