Which form is required for requesting approval of school attendance for children over 18?

The correct form required for requesting approval of school attendance for children over the age of 18 is the 21-674. This form is specifically designed for parents or guardians of dependents to notify the Department of Veterans Affairs regarding a child's school attendance, particularly when the child is over 18 but still enrolled in educational programs.

The use of this form ensures that the VA can properly assess and maintain records of the dependents’ educational status, which is essential for determining eligibility for certain benefits related to education. By providing this information through the 21-674, parents or guardians can help facilitate the continuation of support for veterans' dependents who are pursuing higher education or vocational training.

Other forms, while relevant to different aspects of the VA's processes, do not pertain specifically to the approval of school attendance for children over 18. Thus, the 21-674 is the appropriate and required form in this context.