Me12355, Shidduchin is one of the exceptions that the Chafetz Chaim makes, provided the following conditions are met :
A.the person making the request must it is for the pirpose of a shidduch
B. The request cannot be made from someone knownto be an enemy of the prospect
C. The response must be carefully thought thru and not exaggerated
D. It is permitte to report only those negative comments that pertain to the shidduch. However,if , for example , the engagement has already taken place and the newinfo is unlikely to break it, you cannot say
E. If the requestor is known to be indiscreet, you cant answer
The Pischei Tshuva holds that it is an avairah to withhold information regarding a shidduch
