Update: Tag no longer exists.
There are presently two Open Qs tagged merging:
One concerns merging questions (specifically two that have since been deleted) and the other user accounts (for a specific user).
In general, where a tag is applied to two different questions it will not automatically be deleted (each causes the other to be maintained). However it seems that even a single instance may not automatically be deleted when used for WAmeta.
Another, and more popular use, for “merging” is in connection with tags, though in that sense we have tag-request whose Usage guide is at present:
This tag is for requests to replace one tag with another existing tag. It also applies to requests that one tag should be merged into another, or simply abandoned.
Possibly related:
user-accounts whose Usage guide at present is:
Refers to user accounts either generically, or across the network.
login whose Usage guide at present is:
For issues connected with site access to Web Applications as a registered user.
and, perhaps, without Usage guides at present:
account-association
users
user-profiles
If merging is to be retained, should it apply to both “accounts” and “questions”, and if not, to which, or to neither?