Copy data from one file to another

Can you lend me a hand and share the steps to loading a saved tag? Below is as far as I can get.

  1. Right-click on audio file -> Open with -> MP3Tag.
  2. Select the file in right pane -> File.
  3. ?

And now you see the tag data for that file in the tag panel and in the columns of the file list.

No. If the file does not have any tag info, the fields are empty. There seems no way to import data from a saved metatag. It appears that MP3Tag can export tag info but not import. So what purpose is there in exporting the tag?

It is not clear to me what you mean by

MP3tag displays the data that can be found in the tags.
If you suspect that data should be there but is not displayed, then please show us a screenshot of the extended tags dialogue Alt-T of a single file and a screenshot of the settings which options you have set for MPEG files
Ctrl-O>Tags>Mpeg

Sorry for not being clear. Here is what I am trying to do:

  1. Open an MP3 file with MP3Tag.
  2. Enter tag info.
  3. Export the "configuration" in html format.
  4. Open a new version of the MP3 file (same song revised in my DAW).
  5. Now I would like to Import the data exported earlier, instead of typing it in again. I see no way to import the saved info.

You can copy an paste a whole tag.
Select the original file
Press Ctrl-C or use Edit>Copy
Select the "new version of the MP3 file"
Press Ctrl-V or use Edit>Paste

If you want to import from a text file, use Convert>Text file-Tag

No need for exporting. Here is a method which copies only tags, not whole files:

Let's assume that you have two folders, one with files that are tagged (folder name SOURCE) and one with files without tags (folder name TARGET). Both folders must contain the same file names and the same number of files.

  1. Load both folders into the Mp3tag selection window.
  2. Sort the files by Path and sub sort by Filename (see how below).
  3. Select all the files in the SOURCE folder.
  4. Choose Tag Copy from the context menu.
  5. Choose Edit|Invert Selection from the menu bar.
  6. Choose Tag Paste from the context menu.

For accuracy it's important to keep the files in both folders sorted the same way. You can do this by modifying the Path column sort formula in Customize Columns. Simply add the filename to the Path "Sort by" formula, like this:

%_folderpath%%_filename_ext%

Now sorting by Path will also keep the filenames sorted within each path, as required for the copy and paste steps above.

Thank you for your kind help. I can now copy & paste tag info from one file to another. But I am still unable to import an exported tag.

MP3Tag lets me export a tag, such as a *.html file; but if I want to import the saved tag in a new song, there seems no way to import it.

What is the point in exporting tag info if it cannot imported?

There is absolutely a method to import tags. This was answered less than 24 hours ago.

That HTML is the only format is not correct. MP3tag exports tag data to plain text files. You as the user can create exports that conform with the html standard.
You can also create exports for a plain text export or text files with more rigid rules like csv, rtf, xml or any other format for which you know which additional markups have to be added.
See here for a collection of user-contributed export scripts:

To import data from text files you have 2 functions:

and

but in both cases you have to take care that the text file is in a suitable format.

As plain text files have the limitation of not being capable of transporting binary data like pictures, it looked appropriate to suggest the copy&paste method in your use case where you have source files and almost identical target files. Copy&paste also transfers embedded pictures.

Forgive me if I fail to understand, but it has become apparent to me that MP3Tag simply does not support import of an exported tag. I do not want to copy tag info from one MP3 file to another: In Audacity, I export (save) tag info as an XML file; then, whenever I mix down a new version of a song and want to load saved tag info, I just open it and import the info. But the Metatag editor in Audacity does not support album art, which is why I use MP3Tag. Perhaps Florian will add the the bility import what it exports in a future release. Despite this limitation, I still think MP3Tag is a great app.

Perhaps a look at the linked parts of the documentation will shed some light?
Your claim that

is simply not true.
You have not yet told us what the exported tag data looks like.

I don't understand why you're so fixated on laboriously exporting data and then importing it again, when there's a much easier and faster way to transfer tag data directly from one file to another. (See Doug_Mackie's post and the documentation.)

Since you have a source file with the desired tag fields, otherwise you wouldn't be able to export them, you simply select that file, copy the tag data to the clipboard with CTRL-C. Then you select the target file and paste the tag data there with CTRL-V. All this without the cumbersome export and import workflow, and it also avoids the need to export and re-import the cover and text data separately.

Of course, Mp3tag also has a functioning export and import function, although the export function goes far beyond simply exporting data for the purpose of re-importing. The export function allows you to create a variety of custom lists, for example, that simply serve the purpose of creating a beautifully designed list of your music files, e.g.,

https://download.mp3tag.de/export/latex_osmo_covers.pdf
https://download.mp3tag.de/export/html_dano_albumlist_js_f.html

You should also be willing to avoid slavishly sticking to your current workflow if the software you're considering offers more practical, simpler, and faster options.