I found this list of dogmatic beliefs De FIDE online, these should oblige every Catholic;
catholicfirst.com/thefaith/churchdocuments/dogmas.cfm
Dogmatic Formulation and
Positive Foundation of the Dogma of the Trinity
The Antitrinitarian Heresies and the Doctrinal Decisions of the Church
In God there are Three Persons, the Father, the Son and the Holy Ghost. Each of the Three Persons possesses the one (numerical) Divine Essence. (De fide.)
The Triple Personality of God
In God there are two Internal Divine Processions. (De fide.)
The Divine Persons, not the Divine Nature, are the subject of the Internal Divine processions (in the active and in the passive sense). (De fide.)
The Second Divine Person proceeds from the First Divine Person by Generation, and therefore is related to Him as Son to a Father. (De fide.)
The Holy Ghost proceeds from the Father and from the Son as from a Single Principle through a Single Spiration. (De fide.)
Speculative Explanation of the Dogma of the Trinity
Speculative Explanation of the Internal Divine Processions
The Son proceeds from the Intellect of the Father by way of Generation. (Sent. certa.)
The Holy Ghost proceeds from the will or from the mutual love of the Father and of the Son. (Sent. certa.)
The Holy Ghost does not proceed through generation but through spiration. (De. fide.)
The Divine Relations and Persons
The Relations in God are really identical with the Divine Nature. (De fide.)
The Three Divine Persons are in One Another. (De fide.)
All the ad extra Activities of God are common to that Three Persons. (De fide.)
The Father sends the Son: the Father and the Son send the Holy Ghost. (Sent. certa.)
The Relation of the Trinity to Reason
The Trinity of God can only be known through Divine Revelation. (Sent. fidei proxima.)