The IDN WG's comparison document [IDNComp] describes three potential main architectures for IDN: arch-1 (just send binary), arch-2 (send binary or ACE), and arch-3 (just send ACE). RACE is an ACE, called
Row-based ACE or RACE, that can be used with protocols that match arch-2 or arch-3. RACE specifies an ACE format as specified in ace-1 in [IDNComp]. Further, it specifies an identifying mechanism for ace-2 in
[IDNComp], namely ace-2.1.1 (add hopefully-unique legal tag to the beginning of the name part).In formal terms, RACE describes a character encoding scheme of the ISO 10646 [ISO10646] coded character set and the rules for using that scheme in the DNS.