Source: Elines

Section 22.B.2. of our JCBA addresses the circumstances under which documents may be added to our personnel files: 

The Company shall not place an adverse document in a Flight Attendant's personnel file more than thirty (30) days following receipt by the Company. Prior to placing an adverse document in a Flight Attendant's personnel file, the Company shall notify her/him, and provide an opportunity to attach relevant comments.

Section 22.C.2. outlines the circumstances under which a complaint letter can be entered into a Flight Attendants work history.  Flight Attendants are encouraged to monitor their work history to ensure all entries in the work history comport with the requirements of the Contract.

All complimentary and complaint letters will be removed at the first opportunity from the Flight Attendant's file after a period of twelve (12) months of active service from the date of their receipt, provided there have been no other complaint letters during that period. In the event other complaint letters are received at any time during the twelve (12) months, the letters will be retained in the file until such time that there is a twelve (12) month period of active service with no complaint letters received. In the event discipline is imposed, the complaint letter(s) used as a basis for the discipline will remain in the Flight Attendant's personnel file for the duration of the discipline.

Contact your Local Grievance Committee for further clarification.