id	definition
01	First grade
02	Second grade
03	Third grade
04	Fourth grade
05	Fifth grade
06	Sixth grade
07	Seventh grade
08	Eighth grade
09	Ninth grade
0K	Kindergarten
10	Tenth grade
11	Eleventh grade
12	Twelfth grade
20	Non-Degree or Temporary Undergraduate in Postsecondary school
21	Postsecondary First Year Student
22	Postsecondary Sophomore
23	Postsecondary Junior
24	Postsecondary Senior
25	Postsecondary Post-Baccalaureate Student
26	Postsecondary Non-Degree Graduate Student
27	Postsecondary Professional Student
28	Postsecondary Master's Degree Student
29	Postsecondary Doctoral Student
30	Postdoctoral Student
31	Postsecondary Bachelor Preliminary Year
32	Postsecondary Fifth Year Student
33	Postsecondary Masters Qualifying Year
AD	Adult
AS	Associate Degree
BD	Baccalaureate (Bachelor's) Degree
C2	Medical Test (Trial)
DD	Doctoral Degree
EL	Elementary School
EM	Employment
HG	High School Graduate or Equivalent
HS	Attended high school, but did not graduate.
IF	Infant (0 to age 2)
IN	Intramural
MD	Master's Degree
MS	Middle or Junior High School
NO	None
P0	Pre-Kindergarten Level 0
P1	Pre-Kindergarten Level 1
P2	Pre-Kindergarten Level 2
P3	Pre-Kindergarten Level 3
P4	Pre-Kindergarten Level 4
P5	Pre-Kindergarten Level 5
PC	Postsecondary Certificate or Diploma
PD	Professional Degree or Certification
PF	Professional
PK	Pre-Kindergarten
PS	Some Postsecondary (e.g., college)
SS	Secondary School
UN	Ungraded
VR	Varsity
VS	Vocational School