Canonum De Ius Rex
Canons of Sovereign Law
II. Sovereign
2.5 Roman Law Form
Article 55 - Municipium (municipality)
Canon 5779 (link)
An important distinction with Municipium was the fact that municeps (lowest citizens) were considered citizens of the city / town they were born, regardless of their location since birth. Therefore, whenever a census was called for the purpose of collecting taxes (tribute), municeps were required to return to their birth town.