\override and \revert

[Timothy Lanfear]

https://lilypond.org/doc/v2.22/Documentation/extending/intermediate-substitution-functions 
describes \temporary \override and \revert as push/pop pair operating on 
a stack of grob properties so the previous value of the property can be 
recovered. On the other hand, the example of \revert in 
http://lilypond.org/doc/v2.22/Documentation/notation/the-override-command 
does not use \temporary. It does seem that the default value of the 
property is restored if the stack becomes empty. Is it true that the 
default is restored? Is there any advice on the best way to use \revert?

--
Timothy Lanfear, Bristol, UK.