These are WID tables, their history and data sources.  Tables can come in 4 types –

Lookup Tables – these define the codes used to describe data types in data tables

Data Tables – these contain the data for various sources

Crosswalk Tables – these relate different data structures

Admin Tables – these describe the tables in the database

While Core (required) tables have complete content, non-standard (not required) tables may not.  If you have questions that are not answered by the documentation, try asking in our forum or emailing Amanda.