Blue Club is a bridge bidding system, developed mainly by Benito Garozzo. It was used by the famous Blue Team and became very popular in the 1960s and has been in decline since.
The main features are:
Blue Club is less fashionable these days but it was still used by a few pairs in the 2013 World Bridge Olympiad: VanProoijen-Verhees of the Netherlands, BScornell-Bach of New Zealand and Newell-Reid New Zealand.