After doing a Tax Status update, you may notice in the Notes field of an Organization's IRS data that there is now a 4 digit Classification Code.  The IRS recently implemented this Classification Code to capture up to 4 codes related to an organization. The valid classification codes are: 1, 2, 3, 4, 5, 6, 7, or 8.  The code may be a 1-4 digit entry.  After the codes, there are trailing zeroes.
Example for a 501(c)(3) Organization: Classification Code of 1000 would be 1 (Charitable only). 
Classification Code of 1200 would be both 1 and 2 (Charitable and Educational).

Below are the individual codes for 501(c)(3) organizations:
1   Charitable Organization
2   Educational organization
3   Literary organization
4   Organization to prevent cruelty to animals
5   Organization to prevent cruelty to children
6   Organization for public safety testing
7   Religious organization
8   Scientific organization

All codes can be seen here: