The upcoming revision of CREPDL is intended to combine the best parts of Unicode regular expressions and the W3C notation. CREPDL is expected to work nicely for huge subsets. The F# implementation of CREPDL is publicly available.

The next step is to use CREPDL for comparing different subsets covered by different fonts. It is not easy to directly compare two CREPDL scripts. However, if there is a list of all grapheme clusters in Unicode, validation of this list against two CREPDL scripts can provide definitive answers.