This field is from the IRS Form 1023 Application for Recognition of Exemption, and is used to specify the statutory reason why an organization qualifies as a 501(c)(3) public charity or private foundation.
Since the explanations are long and cannot be abbreviated sufficiently, this note provides the full description of each category:
IRS DESCRIPTIONS
00 All organizations except 501(c)(3)
02 Private operating foundation exempt from paying excise taxes or investment income
03 Private operating foundation (other)
04 Private non-operating foundation
09 Suspense
10 Church
11 School
12 Hospital or medical research organization
13 Organization which operates for benefit of college or university and is owned or operated by a governmental unit
14 Governmental unit
15 Organization which receives a substantial part of its support from a governmental unit or the general public
16 Organization that normally receives no more than one third of its support from gross investment income and unrelated business income and at the same time more than one third of its support from contributions, fees, and gross receipts related to exempt purposes.
17 Organizations operated solely for the benefit of and in conjunction with organizations described in 10 through 16 above.
18 Organization organized and operated to test for public safety
NCCS ABBREVIATED DESCRIPTIONS
00 All orgs except 501(c)(3)
02 Private operating foundation exempt from paying excise taxes or invest. income
03 Private operating foundation (other)
04 Private non-operating foundation
09 Suspense
10 Church
11 School
12 Hospital or medical research org
13 Operates for benefit of college/ univ. & owned or operated by governmental unit
14 Governmental unit
15 Receives substantial part of support from governmental unit or general public
16 Normally receives < 1/3 support from gross invest. & unrel. bus. inc. & >1/3 support from contribs, fees & gross receipts rel. to exempt purposes
17 Operated solely for benefit of & in conjunction with orgs in 10-16 above
18 Organized & operated to test for public safety