You're right - that's my mistake. `import:merge` is a tag I was using internally for items where I was unsure if they could be merged with existing features using only assumptions made based on geometry/location. (The vast majority of features can be merged based on that assumption.) I should have removed that tag before uploading. I'll fix that asap.

Also, I'm not sure how I missed the fact that I'm supposed to be linking to the documentation. It definitely makes sense to do that and I'll include it in future changesets. Documentation is here: https://wiki.openstreetmap.org/wiki/Utah/CacheValleyAddressImport