Raised on 2013-01-18
By Richard Ishida

3.10 Other Characters Deprecated in Unicode
https://www.w3.org/TR/2013/NOTE-unicode-xml-20130124/#OtherDeprecated

"What to do if detected: ...; where possible, in an editing environment, a preferred alternate encoding may be substituted"

Not sure I know what this means, but if it means changing the encoding of the document because of the deprecated characters, I think that's wrong.