This option enables reading of subdirectories.
You can enter a favorite directory here and quickly jump to this directory via File → Favorite directory or the corresponding button from the Toolbar.
You can now specify the startup behavior of Mp3tag. Empty starts with an empty File List. Previous starts with the folder which was loaded the last time you’ve used Mp3tag. Favorite lets you choose a explicit folder (see above) that is loaded on startup.
Cover art directory
This option specifies a default directory that is displayed when adding cover art. Besides fully-qualified path names, you can provide relative path names and use placeholders.
If no default directory is specified or the directory cannot be opened, Mp3tag opens the directory of the first selected file if it contains cover art or the current working directory in all other cases.