INEGI: autonomous public body responsible for regulating and coordinating the National System of Statistical and Geographic Information in Mexico.
CVE_MZA means "Clave de Manzana (Block Code)".
Where "Manzana" means a territorial extension made up of one or more properties for residential, commercial, industrial, service or vacant land use; it can generally be surrounded, is delimited by roads and sometimes complemented on some of its sides by a defined feature.
The blank space is an error that must be fixed.