For the person who is not attending school (if attending school or never attended school, mark the 0 boxes)
[Applies to questions 23 -24]

23. Last grade passed

Questions 23 and 24 - For persons who do not attend school

For persons who concluded or discontinued the course they were attending, mark, in Question 23, the last grade or year concluded in the highest level course and, in Question 24, the level of this course, according to the designation in effect at the time of the interruption or conclusion.
The criteria and concepts for entering the course that was concluded or interrupted are the same as those indicated for the courses attended, ministered in Questions 20 and 21. Consider recording master's degree or doctor's degree only when the person has earned the respective title or approval of thesis.

[p. 49]

For persons who are attending school or who never attended school, mark Box 0 in these two questions.
Only if the person is attending a course at the same level or on a level lower than one already concluded or interrupted, should there be, besides the information about the course they are attending (Questions 20, 21 and 22), information about the highest level course concluded or interrupted (Question 23 and 24).