Edit tag if existing

Hi, there,
I'm trying to edit a tag that exists only in certain tracks with actions. However, if I do it with "Format value" it adds the same tag to files that do not contain it.

Now I would like to edit the tag without adding it to the files that don't have it.

Filter the files that have the special tag before.
i.e
%tagname% PRESENT
or add a filter to the format-value-action
if$(%tagname%,your content,)

1 Like

How do I do that?
I'm new at this condition thing.
Can it be placed in an action?

Just take
$if(%tagname%,your content,)
as your format string in the action.

Edit:
Corrected type error: if$ to $if

1 Like

You mean something like that?
Screenshot_3

obviously replacing by the corresponding label

Trying it that way removes the tag, i.e. it returns z

Edit: If it works, it's perfect. Just what I wanted.

MP3Tag is great.

Thanks you @poster <3