A Cognos Reporting report element name has a suffix like ~1

If a study designer accidentally assigned more than one item in a repeating section with the same Short Question value, Cognos Reporting appends each value with a suffix to uniquely identify it. For example, if two itemsets share the Short Question VSItemset, Cognos Reporting identifies them as VSItemset and VSItemset~1.

As a best practice, study designers should make sure that each item in a study has a unique Short Question value.