Cards can be linked to netention objects and the content of the card can become tags, personas, etc in a semantic environment.
The cardboard is a data visualization system, by using strings, it can be turned into a gantt project diagram.
The end can be defined by the tasks and reviews, and vice versa.
Cards could be printed from netention, with barcode or any ID system.
Even money can be used as a metadata currency.
The unique ID can be linked to any netention object...