The information I have been able to find seems inconsistent / incomplete.
For QO breakers there is a handle tie from the manufacturer (Square D / Schneider Electric), which is part QO1HT.

However the documentation is sparse and doesn't state which specific breakers this is meant for. I was expecting an exact listing, much like you would see for a panel calling out which breakers you could use.
A catalog document does state "Converts any two adjacent 120/240 Vac 1P QO circuit breakers to independent trip 2P. " Based on that you might assume its OK to use their handle tie with any single pole QO breaker. But there is contradictory information. At least I found a comment posted by the manufacturer to a customer question stating:
From SchneiderCustomerCare:
April 27, 2016
...the QO1HTCP is only for the QO load centers. We
offer the HOM1HT for the Homeline. However neither will tie Tandem
breakers together. We do not offer a breaker tie for your requested
application.
(source)
(Not sure why they use a slightly different product # in that comment, though it seems like the same thing. Might be because it is sold in a qty > 1).
So if in doubt, probably a call to the manufacturer would be in order.
And though this is just about QO breakers I'd be circumspect about any brand / model unless the instructions are crystal clear.