(Mods, if there's an existing thread that's better suited, please move. I searched for recent discussion but didn't find anything.)

A relative is flying IAD -> Canada -> Australia next month and I've been trying to advise on security measures. But I haven't flown to/in the US is a decade, so I'm a bit out of touch regarding checked baggage.

Is there still a requirement to only use TSA locks on checked baggage? Are non-TSA locks still cut off or destroyed?

She may be using an old (1970s) hardsized suitcase with built-in combo locks in the latches of the case; from memory the only way to keep the latch closed was to lock it.

I know all the arguments about not using locks at all, only travelling with hand luggage, etc, so please, just advice on the current situation with locks. TIA.