Does a 'stable' deferred trigger execution order exist? Is housekeeping for deferred trigger fire events done in one of the system catalogues?

Hi,

If during a transaction a number of deferred triggers are fired, what will be
their execution order upon the commit?

Will they be executed in order of firing or alfabetically or something
entirely different? The docs only mention regular triggers being executed
alfabetically.

And equally important in case it is in firing order, is this order regarded as
'stable' between releases?

Also, are the fire-events of deferred triggers kept in a system catalogue
somewhere, .i.e. would it be possible upon a first time execution of a
deferred trigger to avoid any additional executions of that same trigger that
got scheduled earlier in the transaction due to multiple fire events ?

--
Best,

Frank.