Tracking changes to nationalmusym

[hammerly]

In performing Quality Assurance on projects, it would be advantageous to be able to quickly identify not only changes to musym in the spatial data, but also changes to the nationalmusym. For example, in some complex projects where different musym is used in different counties, but the nationalmusym is the same, one could easily identify errors that may occur when spatial edits have inadvertently created unique musym in the same county, yet have the same nationalmusym. The opposite situation could also be identified easier - spatial edits that have inadvertently created the same musym in a county, yet have different nationalmusym.

This error is already quickly and easily identified when making the legend changes in NASIS. In NASIS, an error is immediately shown on the affected rows and it does not allow those edits to be saved. The error is not immediately clear however when making the spatial edits. I suggest adding a column to the RTSD database which would identify the original nationalmusym and the new, or intended nationalmusym, and ask that it be populated when performing spatial edits to projects. A tool could be developed then to check these fields and verify that there are no errors. I discussed this issue with @alenars.