Conversation so far:
When was the Rem Koolhaas' European Flag proposal written?
Following the signing of Treaties of Nice in May 2001, Rem Koolhaas was invited to discuss the necessities and requirements of a European capital.
Was the Rem Koolhaas' European Flag proposal accepted finally?
Since the time of the first drafts of Rem Koolhaas' barcode it has very rarely been officially used by commercial or political institutions in the EU.

Question: Is there any other person who contributed to the proposal?
Self-contained rewrite: Is there any other person who contributed to the European Flag proposal besides Rem Koolhaas?