The legacy file format of the first 2020 Public Law 94-171 data (100% count) release (August 12, 2021) is the format used by the Census Bureau in previous decades. For the 2020 Census, the Bureau also released the data in another format (September 16, 2021) for direct use with database and spreadsheet applications.
The data provided with Maptitude for Redistricting is sourced from the first (legacy format) release from the Census Bureau. Please note this Census Bureau statement:
“The data included in the August and September deliveries will be identical. States can use either the August delivery or the September delivery as appropriate, taking their own statutes and constitutional requirements into account. The Census Bureau considers both releases to be official and fit for use.”