StringPrep use newer Unicode then StringPrep RFC 3454 ----------------------------------------------------- Key: ELY-48 URL: https://issues.jboss.org/browse/ELY-48 Project: WildFly Elytron Issue Type: Bug Reporter: Jan Kalina Assignee: Darran Lofthouse Priority: Minor RFC 3454 (StringPrep) define table of unassigned codepoints by Unicode 3.2: http://tools.ietf.org/html/rfc3454#section-7 But StringPrep implementation use {{java.lang.Character.getType()}}, which use newer Unicode, where same of defined unassigned codes are already assigned. Examples: codepoint {{0x0221}}, {{0x0234}} and {{0x02EF}} All are defined in RFC as unassigned but in Unicode 4.0.0 they are assigned: http://www.fileformat.info/info/unicode/char/02EF/index.htm I think using of newer Unicode can be tolerated, but it can depend on purpose of this profile of encode function.