Attention: The Marketo Community will undergo scheduled maintenance on Tuesday, August 20th between 10-11 PM PDT. During this time, the Community and its content will not be accessible. We apologize for any inconvenience this may cause.
It's basically to reduce clutter in the UI. Assets you don't want to take down but you also aren't going to use them anymore in the future and don't need them cluttering the search. EDIT: Archiving, I mean.