Catechism of the Catholic Church §2199 — excerpt
The fourth commandment is addressed expressly to children in their relationship to their father and mother, because this relationship is the most universal. It likewise concerns the ties of kinship between members of the extended family.
This translation is under copyright, so only the cited words are quoted here. Follow the link for the full text. Translation: English translation of the Catechism of the Catholic Church, 2nd ed. (Libreria Editrice Vaticana), as posted at vatican.va.