Each student has 4 defined characters represented by 4 "0"s if not entered for the student. The school defines what the 4 characters represent, and they are “secret” to the school in that only school staff know what they mean. Each defined character may be a letter A to Z, or a number 0 to 100. They are used as a quick means to identify groups of students. For example, a bilingual school may use defined character 1 to represent whether the student is English or French. Each student will have an E or F recorded in the 1st defined character.

Define characters is set on the student record under enrollment> flags > edit

scroll to the bottom of the page and set the defined character.

If you want to reset the flag to nothing you need to change the value to 0 (zero) and click done, as show below.

As you can see the define character has now been reset to 0