I'm using ArcCatalog 10.2.2 to update the metadata for several geo-datasets. The Tags section is more visible in the Overview Item Description and looks just like a list of theme keywords. But it's not. In my testing, I noticed that if there are no theme keywords the tags get exported as keywords when going from ARCGIS2FGDC. If there are both theme keywords and tags then the keywords are exported.
What's the difference between Tags and Theme Keywords?