The displays on the gateline at St Pancras High Level have now been
changed to state "ITSO/Tickets" instead of "Oyster/Tickets" as they
previously did. Whether they actually now accept ITSO cards is hard to
check without one.
(They have always rejected Oyster cards previously, even when FCC
trains are running from the high level platforms.)

I think this is the first gateline mentioning ITSO acceptance.