Directive of Pope John XXIII Restoring Latin as the Language of Instruction in All Seminaries and Pontifical Institutions

Given that Ralph McInerny's book *What Went Wrong with Vatican II: The Catholic Crisis Explained* has recently been bandied about (see https://christianity.stackexchange.com/questions/96550/who-said-god-did-not-become-man-in-order-for-man-to-become-a-theologian and https://christianity.stackexchange.com/questions/96557/what-is-meant-by-catholic-truths-in-otts-fundamentals-of-catholic-dogma) , I would like to point out that at the beginning of that book on pg. 7, one finds: >It is forgotten now that early in his papacy he [Pope John XXIII] issued a directive requiring Latin to be fully restored as the language of instruction in seminaries and pontifical institutions. QUESTION: Specifically, what was the directive of the said Pope fully restoring Latin as the language of instruction in seminaries and pontifical institutions; and was it ever followed? What is its status today?