A confirmation letter includes the salary, joining date, confirmation date, designation and job description of an employee. Later, if the employee moves to another company this letter acts as proof of the position n salary he held in his previous job.
Include a subject line that clearly states the purpose of the letter, such as "Notarized Letter for Proof." Begin the letter with a formal salutation, using the recipient's title and last name. In the first paragraph, briefly explain the reason for writing the letter and the specific proof you are providing.