Attorney General Bill Pryor issued a memorandum to all Alabama city and county school superintendents.
The memo advises them of the rights of public school students to hold prayer vigils for the annual See You at the Pole event.
This year's vigil is scheduled for Sept. 18.
The attorney general says participation may increase because of the closeness of the event to Sept. 11.
See You at the Pole prayer vigils are usually scheduled at the beginning of each school year.