This is the secret key to the web feed of your watchlist. Anyone who knows it will be able to read your watchlist, so do not share it. If you need to, you can reset it.
MediaWiki:Prefs-help-watchlist-token2
From Hawk Wiki
This is the secret key to the web feed of your watchlist. Anyone who knows it will be able to read your watchlist, so do not share it. If you need to, you can reset it.