A department head or designee may warn an employee either orally or in writing as a disciplinary measure. A copy of any written warning shall be placed in the employee's personnel file and may be used in considering further discipline, demotion, withholding of salary increases, and other personnel transactions when such actions occur within twelve (12) months of the date of issuance of the written warning. The employee shall sign one copy signifying he/she has received and read it and shall retain one copy for his/her own records. The written warning shall bear the signature of the issuing official.
Ill. Admin. Code tit. 80, § 620.1220