In light of your question, some thinking around the answer from @Midavalo, the way ArcGIS Pro has been positioned as an application of ArcGIS Desktop, and my growing unease with one of the compromises that Tagging ArcGIS questions makes, my views on how best to tag ArcGIS Desktop questions have evolved.
ArcGIS Desktop is a product from Esri, and 3D Analyst is one of its extension products. Together, they provide five ArcGIS Desktop applications:
- ArcMap, ArcCatalog and ArcGIS Pro are unlocked by an ArcGIS Desktop core license.
- ArcGlobe and ArcScene are unlocked by an ArcGIS 3D Analyst license.
In light of ArcGIS Pro becoming much more mainstream, and inevitably supplanting the other four (ArcGIS Desktop 10.x) applications, I think the best way to tag new questions may be:
- arcmap for questions about ArcMap
- arccatalog for questions about ArcCatalog
- arcglobe for questions about ArcGlobe
- arcscene for questions about ArcScene
- arcgis-pro for questions about ArcGIS Pro
- arcmap and 3d-analyst for questions about ArcMap that use toolbars and geoprocessing tools that are only available with 3D Analyst licensing
- arcgis-pro and 3d-analyst for questions about ArcGIS Pro that use ribbon tools and geoprocessing tools that are only available with 3D Analyst licensing
With respect to old questions I think a manual retagging campaign should not be undertaken. I suspect we can automate a tag overhaul to a new scheme but it will need to be multi-step, and well planned, so doing that in advance of deciding the desired outcome is premature.
Pending further discussion here, I would plan to overhaul Tagging ArcGIS questions, but my current thinking is that a significantly better ArcGIS tagging scheme than I originally proposed is possible.
A plan for how to implement the above is being fleshed out at Re-tagging to de-emphasize ArcGIS Desktop product in favour of its applications? but doing that will be dependent on achieving consensus in this Meta Q&A first.