If you were to play ETM Victory, you would be familar with these. MAtter of fact, even if you never play ETM victory (or one of the other ETM spin offs), it is well worth it to read the ETM Victory pages... some interesting stuff there... Here is a link to their description of the 2/3 double...
http://www.bridgemat...com/victory.htm That is a very long document, so when you get to that page search for the following (complete with bracket)
[Garozzo 2/3 Doubles]
There are examples throughout the document where doubles are 2/3, this section just describes them....
There is a lot of neat theory sprinkled in that long document, but you might want to take a look at another page with links to some of the more useful ideas you might want to appropriate....this page is...
http://www.bridgemat...com/bidding.htm
Among the neat ideas linked ont is page is
JAcboy 2NT Plus
Transfer responses to 1 of a major opening bid
The complex and the advanced ETM victory 1NT responding structures
ETM Gadget relay (nice)
and more...
Ben