The final two sections of Inter Mirifica comprise an “Appendix.”
So that the general principles and norms of this sacred Synod with respect to the media of social communications may be put into effect, by the express will of the Council, the office of the Holy See mentioned in Number 19 should undertake, with the assistance of experts from various countries, to issue a pastoral instruction.
In 1971, the curia finally released Communio et Progressio, complying with this directive from the council bishops. This pastoral instruction has 187 sections–too lengthy for this liturgist to tackle, given that we have a whole stack of post-conciliar worship documents in the queue. Go take a look at it yourselves, if you care to do so.