Feel free to move this message elsewhere in the forum if it doesn’t belong here.

I am using an RSS reader that allows one to put the feeds (not the feed items, the feeds) into folders in a hierarchical tree. I have lots of feeds (many of them are not very active, like new releases by projects on CodePlex), probably between 200 and 300. I would like to be able to put a feed "into more than one folder" as the Tabbles phrase goes — i.e., I’d like to be able to tag them.

Tabbles would allow me to tag the feed URLs but then the messages themselves are not within the system. There would certainly not be any automatic tagging of individual messages by feed (analogous to automatic tagging of files in a folder). And I would have to read the messages in the various blogs on the web rather than in a uniform local format that I can store.

So I am asking if anyone knows of an RSS reader (online or offline, free or for money) that allows one to tag feeds (and then allows retrieval of messages based on the tags of the feed they appear in).

I did find some links to one such reader but it seems that the product or service is no longer offered.