Few years ago, I was really delighted to discover the tags in google mail, and how powerful the concept was, as compared to the bad old folders.
I was very happy again to see that Feng Office also support the Tags feature.
Yet, this is definitively frustating that we can select only one tag at a time, and a real underuse of the concept.
Please ! please ! Add the possibility to say something like "tag1 and tag2 but not tag3", etc.
A simple graphic interface could be to add "+" and "-" button near each tag, so that one can activate and/or desactive any number of tags.
