I'm looking for a way to mark all items from a specific RSS feed as unread in Google Reader.
Is there a way to do this?
I don't believe there is. I've looked a few times and never found a way to do it
You can't mark multiple posts in Google Reader as "unread". You have to do it one by one.
The only recourse you have is to turn on keyboard shortcuts and go through the list tapping j m to mark all that you can as unread.
But before you can unmark as read, when viewing the feed, select Items older than two weeks from the "Mark all as read" menu to allow for this.
Any older and you're left just looking at them in a "read" state.