Label vs ID

[giosce]

We show the label but we would like to tell people to use the ID. Labels can have spaces, for example "Benefits and Tax Credits" but that can't be used as a GitHub tag (can't have spaces). In this case, the ID is already set to benefits-taxes. If as one of the first usage of taxonomy is to suggest people how to tag their project, we need to convey that they need to use the ID instead of the label. For items at top level, the ID is shown on mouse-hover, I doubt it is enough and currently the ID doesn't show for lower level items.