Question:

I say 2 Diamonds, in response to a 2 Clubs opener(strong)
tells my partner nothing except that to bid his strong suit 2 NT is
the bust hand.  My partner disagrees. Who is right??   

My Two Cents Worth:

The key here is that you and your partner need to agree on what to do in this 
situation.  Listed below are three of a number of ways to handle responses to 
strong opening 2 bids:

1) 2NT in Standard American is used as the negative response (0-7 HCP) when all
opening two bids are strong.  Any other response will show at least 8 HCP.  New
suits bid show 5+ cards, and with a balanced hand, bid 3NT with 8+ HCP and no
support for partner's suit.  No alerts are required.  Point ranges may vary
slightly depending upon partnership agreement.  Ranges listed here are just
a general guideline.  

2) 2D in Standard American is used as the negative response (0-7 HCP) when 2C is
strong and other 2 of a suit bids are weak.  Any other response will show at
least 8 HCP.  New suits bid (other than 2D) show 5+ cards.  2NT shows a balanced
hand with 8-10 HCP and no support for partner's suit, and 3NT shows 11+ HCP.  No
alerts are required.  Point ranges may vary slightly depending upon partnership
agreement.  Ranges listed above are just a general guideline.

3) 2D waiting is also a popular treatment over a strong 2C bid.  Point ranges may vary 
slightly depending upon partnership agreement, but the ones listed below are a general 
guideline.  The 2D response denies 1 1/2 or more quick tricks*, but does not necessarily 
deny points.  Any other response promises at least 1 1/2 quick tricks*.  New suits 
(except for 2D) show at least a 5 card suit.  2NT shows a balanced hand with 7-10 HCP 
and no support for partner's suit, 3NT shows 11+ HCP.  After partner shows their suit, 
you can show the negative response by doing the following:

Partner bids 2H or 2S, bid 3C to show 0-6 HCP, alertable
Partner bids 3C, bid 3D to show 0-6 HCP, alertable
Partner bids 3D, bid 3H to show 0-6 HCP, alertable

All other bids show what is called a delayed positive response, with 7+ HCP, but
without 11/2 quick tricks*, new suits show 5+ cards, 2NT (if available) shows
7-10 HCP with a balanced hand and no support for partner's suit.  3NT shows 11+
HCP if 2NT bid was available, otherwise, 7+ HCP.

* Quick tricks:*
* A= 1 quick trick
* K= 1/2 quick trick
* AK= 2 quick tricks
* AQ= 11/2 quick tricks
* KQ= 1 quick trick

Please, I beg of you all, don't ask about step responses over 2C!!!!!