I got no problem in http://cutesoft.net/example/general.aspx because the input interface is using Cute Editor. It changed "a & b & c" into "a & b & c" and this won't cause any problem.

 

However, what the problem is there are many different input interface for data entry. The most common one is simple text box. When the text "a & b & c" is input from simple text box, it will be stored in database as "a & b & c" without any conversion of the "&" sign. But, when "a & b & c" is retrieved using Cute Editor interface, the duplication problem will arise. Is there any solution in Cute Editor?