Passing attribute with whitespace value

[Peter Schober]

* Mark Scarbrough <scarbrom at uci.edu> [2022-07-28 16:30]:
> We have a use case where we are trying to pass a value of a single
> space in an attribute.

Maybe I'll regret even askig but would you care to share what that use
case is or rather how a single space can convey the required semantics
(not not any other non-whitespace character)?

-peter