Anonymous, Liber de Praenominibus
“ But every name which has been chosen to define any one of us (Romans) has the same meaning for the person who is to be signified by it. That which is called a proper [name] is different from this, because the family is known by it, for which reason it is also known as a family name (gentilicum) . Other names are distinct due to their order, since one that comes first is a praenomen, one placed after is a cognomen, and one placed at the end is an agnomen. ”
