pub fn is_pubid_char(c: char) -> boolExpand description
PubidChar ::= #x20 | #xD | #xA | [a-zA-Z0-9] | [-’()+,./:=?;!*#@$_%]
A public identifier is a restricted character set, not free text. Nothing
checked it, so <!NOTATION n PUBLIC "a^b"> was accepted.