how disable all outside import of data (freedb, Amazon, etc.)

I set a bunch of tags. In particular, I have a Best Of album, but wanted to have the year each song was released. So I set the year(s) manually.

But after some mp3tag operations, I see that the year has reverted to the year the Best Of album was released.

I would like to disable all lookups with freedb and Amazon and every other entity listed in the Tag Sources pull-down. I just want tag actions to be restricted to what I do explicitly.

How is that done?

Don't touch the Tag Souces pull-down. I don't think anything is retrieved from remote sources without the user explicitly doing so.

Again, thank you for helping out.

Yup, looks like mp3tag isn't the issue. The thing is, I would use Windows Media Player (Version 12.0.7601.17514) to check out the files. And under Tools/Options/Library(tab)/Automatic media information updates for files, these were check-boxed:

(x) Retrieve additional information from the Internet
(x) Only add missing information.

Which may have played a role. I've also read that WMP may have issues with ID3 tags (but don't know enough about this topic). In any event, disabling that feature resulted in at least one persistent problem: Incorrect display of cover art. It would tend to get stuck on one image as one went through a playlist.

That is not a problem if I use Kantaris media player. All tags are intact and the cover art is correct.

Is it the general consensus that Windows Media Player is a problem? I can deal with it, but some less techicaly-minded friends only use WMP and I guess they'll experience cover art display problems (at a minimum).

No. It has its flaws like any other program.
If you can, block WMP in the firewall.
Also, when there are problems with cover art, clear out the cover cache regularly which can be found in a folder called LocalMLS. (It is a hidden folder, so you might need to set the search function accordingly or navigate manually to
Delete the whole folder, it comes back again.
If you are sure that you have your files with embedded coverart, you can safely delete all folder.jpg and albumartsmall.jpg files - as they might not get updated once they are there.
If you use wmp9 you might have to restore the folder.jpg file but you can do that with mp3tag and an action (see the actions for that).

I do have the cover art, but moved into an "images" folder after inclusion via mp3tag. But have had this problem while testing in folders that only contain the mp3 files.

LocalMLS appears to be where the difficulty is. I'm now off to learn more about image art cache and how WMP may get confused.