Can no longer create 2 entries for 1 field in Enhanced Tags

I often create multiple field contents for one field, especially for Album. Usually, I do it by using the double-backslash separator, which then creates 2 entries for Album (each containing one) when viewed in the Enhanced Tags screen. I just noticed, however, that when I'm in the Enhanced Tag screen and attempt to Ctrl-C a Publisher from one record and Ctrl-V it into another record, it overwrites an existing Publisher entry rather than create a 2nd. Is this by design? Is it a recent change? Will it affect the double-backslash
technique? Thanks!

It is by design. In the extended tag view multivalue fields are shown with multiple tag values and not with a backslash in 1 field. So if you want to copy and paste a multivalue field in the extended tag view you have to mark these multiple fields and c&p them together.
Always adding a field with c&p would make it impossible to just copy (not add) the content of 1 field to another.
There was a change made with version 3.21a.

I don't know what you mean by "affecting the double-backslash". You still can use a double-backslash in the tag-panel to create a multivalue field.

Thanks. My specific problem was that I had one Publisher entry for one track. I wanted to copy a different Publisher entry from another track onto a bunch of tracks, one of which already had a different Publisher entry. The result was that the cut and paste wiped out the pre-existing Publisher entry in that one file.. I'm guessing there's no longer an easy way to accomplish my task?.

As you can see from the linked thread, the change was made because it was considered generally expected behavior. An option to be able to choose both options was therefore not implemented.

It remains possible not to copy fields but to transfer the complete or partial content of a tag field via C&P into a field that has to be created manually in the extended tag view in 1 or more files. Of course, this can also be done in the tag panel using the double backslash.

Thanks. I haven't used this Forum before, so I'm not sure I see a "linked thread." If you're referring to the reply in German, that appears to be making the suggestion that the user could have an option to append to an existing field entry or replace it, but the option to append was apparently not implemented (although I seem to remember having done it before with the append effect.

As far as "this can also be done in the tag panel," I'm not sure I can achieve the appending effecdt in the Tag Panel if multiple files are selected and one or more files have existing entries in that field [indicated by ]. If I paste into that field in the Tag Panel with multiple files selected, it will overwrite the field, just as happens now in the Extended Tags window s I've described. I apologize if I'm confused about this.

Yes. As the starter of this thread, I suggested changing the previous behavior, in which a multivalue field was automatically created, at least with an option in which the user had the choice of creating a multivalue field or overwriting the previous field.
Since overwriting was seen as generally expected behavior and the behavior you had previously used to create a multivalue field with the help of C&P was seen as a rather unlikely procedure, the option solution was dispensed with and overwriting was introduced as a general new behavior.

You're right. In the tag panel, C&P of the content for several files and use of the double backslash is only suitable if the files have the same content, i.e. the same content is also displayed in the field and not just "keep".
However, in the extended tag view you can create a new field and paste copied content into "Value" for several files.

Another option is via Converter Tag->Tag or via an action of type “Format Value”.
In your example that would be:
Field: PUBLISHER
Format string: %publisher%\\Pasted Publisher

Thank you so much. I finally understand it now!