When to comment
Use a comment when the selected official reason requires it or when the guide calls for a concise fact that cannot be reported elsewhere.
Keep it factual
Use plain, neutral payroll facts. Avoid opinions, accusations, diagnoses and unnecessary personal information.
Example
explain a required K-code circumstance briefly without repeating the employee’s full history.
Boundary or exception
Do not use Block 18 to correct a reason code, earnings value or date.
Source state
Sources and dependent product claims reviewed July 30, 2026. First-party Canadian-French editorial review is complete. Accountable payroll-domain sign-off remains required before any certification claim; independent linguistic validation remains recommended.