Yes.
The tandem breakers with the rejection tab, are only for use in panels built before UL had a CTL provision, roughly the early 1960's.
But even back then the panel directories showed which locations were intended for use with tandem breakers.
Jim older panels and tandems before CTL's didn't have the rejection and could be put anywhere in a panel with replacements having a label on them that stated "For replacement use only" (unless you meant "without the rejection tab" back then I have never seen anything in these older panel labels that said anything about only using certin spaces, as a mater of fact, as was pointed out Square D's labels all had two spaces some times marked A&B as if they allowed tandems??
CTL tandems had the rejection and will only fit into select slots of a panel made to use CTL's tandem's
QO's had the hook in the back of the tandem that wouldn't allow it to go in a regular slot because the rail didn't have a hole for it, Home Lines have the shorter stab slot that will only go into the notched buss slots.
What I never figured out is most all manufactures including Square D make non-CTL breakers, even the Home Line one's can be purchased as non CTL even though Home lines came out well after CTL's were in the code, ITE also has non-CTL tandems for panels that were out under the ITE brand name long after CTL's were in the code book.
The whole reason UL started limiting how many breakers in a panel was because of a hotel fire that was ruled to be caused by an over heating panel board, UL started limiting panel boards to 42 over current devices, but I thought that was removed from the code in 2008 cycle which was the third time they moved the requirement from 408.15 in the 2002 to 408.35 in the 2005 to 408.54 in the 2008, in the 2008 version they changed the wording to put the manufacture back in control of designing the panel board to have more over current devices but kept the wording that the manufacture must provide means to limit the amount of over current devices to which the panel board is design for, I have seen a couple boards that would allow 54 breakers but these were 400 amp boards.
As far as I know older non-CTL panels are grand fathered in to having non-CTL tandems, I have seen many that had nothing but tandems.
The other thing I never understood on this finding is if a breaker can get hot enough to cause a fire it would seem that the thermo element would have long since tripped so how can it ever cause a fire? I don't know how many times I have had panel boards with breakers tripping because they were running hot, mostly outdoor panels in direct sunlight, get a breaker hot enough and it will trip without even having a load, so how did they ever come to that conclusion in the hotel fire?
Even if tha panel board was found to be the source of the fire I would have looked at if the panel board had a main and if the bus was over loaded, or were the breakers magnetic trip only, both of which would not have anything to do with todays breaker designs and the fact the bus has to be protected at its current rating.