Solresol makes use of a loose category system to add order to the vocabulary, as well as making it slightly easier to guess a words meaning at a glance.
The document Theorié et Pratique introduces a more detailed category system compared to what was demonstrated in previously studied publications. Specifically, it shows categories based on the first group of syllables of a word. For three syllable words, the first group would be the first syllable, and for four syllable words, it would be the first two syllables.
Theorié et Pratique does not include categories for words of four syllables in length and which have one doubled syllable. This document also refers to syllable-length categories as a "clef", more detailed categories as "races", and word groups of six as "families".
First race, of monosyllables and duo syllables
Originally; Premiere race des monosyllabes & des dissyllabes