These change adds CCT codes to a few schools. To explain what these are, they are "Work Center Codes" (Clave de Centro de Trabajo [CCT]), which are unique identifiers for every single school in Mexico for which they operate. Without this number, they cannot issue official certificate for their students.

The code is divided into the following:

- 2 Numbers (Federal Entity)
- 3 Letters (Classifier [1], Identifier [2,3])
- 4 Numbers (Progressive Number)
- 1 Ending letter (Verifying element)

For this, I'm inserting the data for these codes into a new reference value, that is called ref:MX-CCT (or could be renamed to ref:MX:CCT), which would encompass every single one of these.

For more info about the system that handles this program:
https://www.siged.sep.gob.mx/SIGED/index.html

For the entire list of codes, divided by each state:
https://www.siged.sep.gob.mx/SIGED/mapas.html