Tag/info whether a file is in a playlist?

Is there any way to see if a file is part of a playlist?
I have a playlist with my favourite pieces of music and I might wish to add more files, but I don’t know if a certain file is already in the respective playlist and I don’t want to have duplicates in the playlist.
So is there any way to see this?

Duplicates are automatically removed anyway in Plex playlists.

Ah nice to know, than I will just add stuff that I like and let Plex do the rest. Thanks @OttoKerner :slight_smile: