I see one codepoint now has the kIRG_USource property value of "USAT" in the Unihan_IRGSources.txt file from Unihan.zip: U+20991 kIRG_USource USAT-00061
UAX #45 (U-source Ideographs, http://www.unicode.org/reports/tr45/index.html) mentions UTC and UCI but not USAT. UAX #38 (Unicode Han Database, http://www.unicode.org/reports/tr38/) updated the syntax for the kIRG_USource property (but not the description) to U(TC|CI|SAT)-[0-9]{5} so I'm pretty sure it's not a typo. Where can I find a description of the USAT value? Thanks, David McCreedy
