DTR WG activity is currently paused while the topic of data type registries is under consideration by ISO as a potential standard. The next step in DTR work is clearly governance, regardless of the outcome of the ISO work, but if and when an ISO group comes into focus it will strongly influence the proper next steps for the RDA group. A likely outcome is the creation of the third version of the DTR group to work on governance, either in collaboration with ISO or independent of it.
The first two iterations of the DTR WG developed the concept, drafted a data model and expression for types, and then collected use cases to analyze the results. A number of data type registries are currently in use in prototype efforts, details of which can be found in the reports of WG sessions at prior plenaries, the last one of which was P11 in Berlin.
https://rd-alliance.org/wg-data-type-registries-1-2-rda-11th-plenary-mee...
The output of DTR Groups 1 & 2 was approved as an RDA endorsed recommendation and was then accepted as an ICT Technical specification.
http://dx.doi.org/10.15497/A5BCD108-ECC4-41BE-91A7-20112FF77458
https://ec.europa.eu/growth/industry/policy/ict-standardisation/ict-tech...