What's the message name or the message number for error warnings on Skills and Qualifications?

In the manage messages section (Setup and configuration) you can find a message pop-up by using the error number or the message name (a kind of code of the message).

In Skills and Qualifications, whenever we insert an incorrect value in a field, or we don't fill a mandatory field, or we do more than one error.

We would like to know what's the name or message number of this warning, or, if is not known, how to find it (from database? or maybe from page composer or a Document with all the codes and number of the messages)