There are indications that German authorities will soon be publishing a grid shift data file for transforming DHDN to ETRF89, applicable to German geography. While the file has not yet been published, provisions for it have been added. (Note that this implementation was only superficially tested.)

This implementation includes a new Geodetic Data Catalog (grid shift) file named DhdnToEtrf89.gdc. Refer to this file for more information (you can open it with any text editor). The fallback feature of the Geodetic Data Catalog is fully supported by this technique.

Note that the official name may use the designation ETRS89 instead of ETRF89. ETRF89 is consistent with similar transformations which apply to other geographic areas in Europe.