The lexical structure chapter defines the non-terminal uniSymbol as
uniSymbol ::= any Unicode symbol or punctuation
There is a slight ambiguity here: is that description supposed to
be parsed as:
(a) "Unicode (symbol or punctuation)", or
(b) "(Unicode symbol) or punctuation"?
(a) and I thought the report specified that the language's lexemes are defined in terms of Unicode properties so (a) is the only meaningful interpretation. (b) is not particularly meaningful, as your own question demonstrates.