The NTv2 (National Transformation Version 2) file standard was developed by the Canadian government in 1995 to describe shift data for transformations of geographic points from one datum to another (originally from NAD27 to NAD83). This file format has since then come into world-wide use, with over a dozen countries publishing NTv2 files for their areas.
The NTv1 (National Transformation Version 1) is the earlier implementation of the Canadian National Transformation.
Geodesy Transform supports custom NTv2, v1 grid files for datum transforms. Upload NTv2, v1 files and set through the datum settings. NTv2 files are shared across all your projects.