According to the search results, there is no such thing as an "assignment number" in IGNOU. However, there is an "assignment code" which is located on the top right side of the assignment question paper. The assignment code displays the year of the assignments (session) and the validity of the assignment, such as which year it needs to appear in the TEE (Term End Examination). The assignment code helps identify the session and exams for which the student is submitting the assignment. The assignment code is required to be included on the first page of the IGNOU assignment along with other details such as the students name, enrollment number, phone number, submission date, and signature. The assignment code is also known as the "assignment number" in some sources.