[Arkcon]

Originally posted by geoschmo:
The main difference is that you can edit a prototype design. Once you add one to a queue or build one you cannot edit it anymore. You can copy it or upgrade it, but these make new designs.

Geoschmo

I dunno, I think the purpose of the PROTOTYPE label is to let you know that you can edit it. One you add it to a queue, if if you take it off, it's no longer a prototype and can't be edited.