The Unicode Collation Algorithm (UCA) data is being modified to make all digits with the same numeric value sort the same, whether they are European (ASCII), Arabic, Devanagari, or others. In addition, the format of the main data table has changed to omit the (unused) 4th level weight, and some data tables are moved to the Unicode CLDR project.

These and other changes are in the new proposed update: see PRI 235. For the exact list of modifications, see Modifications.