This query finds variables that are assigned a value but are never read. This is usually an indication of a variable that has been orphaned due to changes in code, or a defect in the code due to the omission of the unused variable. The unused variables should be removed to avoid misuse.

Examine the code to see if the variable is no longer needed. If it is unnecessary, remove the variable. Otherwise, update the relevant code to use the variable.

SEI CERT C Coding Standard: MSC13-C. Detect and remove unused values.