>>Remember the conversation we had few days ago when I could not see her messages since they were in the Chatter category I filtered.
>>
>>Yesterday I cleaned up my replies a bit and today I noticed a bunch of the replies in the thread that was in Chatter and I didn't see before.
>>
>>For me this would be a desired behavior, actually, but I know it contradicts your recent definition of all filtering applied.
>
>Yes, exactly, as I mentioned in the private message, this would then be the correct behavior as the filtering on that category came after she created the message, which caused some replies to you. Basically, twit filter, category filter and thread filter are effective on the upcoming only.

I'm not sure I understand. I filtered Chatter forum's categories in May, if memory serves.