Annex E (informative)
Conformance with UAX #31
[uaxid]
E.3
R2 Immutable identifiers
[uaxid.immutable]
1
#
An implementation may choose to guarantee that the set of identifiers will never change by fixing the set of code points allowed in identifiers forever
.
2
#
C++ does not choose to make this guarantee
.
As scripts are added to Unicode, additional characters in those scripts may become available for use in identifiers
.