There are issues, persons and situations for which it is better not to talk about them.
Known is the prestige and mark of culture that the proper use of a synthetic Latin phrase gives to a sentence, to a thought, to an affirmation. There are many such phrases that many centuries of Latin culture have passed to us in the West, till the point that there are many dictionaries or indexes of Latin phrases to help us to find the appropriate to the particular context.
Nec nominetur is one of those Latin phrases, although not the most common. Literally it means " let it not even be named, let id not quoted " . Its origin is in the letter (epistula) that Paul addressed the people of Ephesus (Turkey), (Ephesians, 5,3-4) where we read the whole sentence:
But fornication, and all uncleanness, or covetousness, let it not even be named among you, as becometh saints; nor filthiness, nor foolish talking, or jesting, which are not befitting: but rather giving of thanks.
In Latin (the Jew Paul speaks and writes Greek language):
“Fornicatio autem, et omnis immunditia, aut avaritia nec nominetur in vobis, sicut decet sanctos; aut turpitudo, aut stultiloquium, aut scurrilitas, quæ ad rem non pertinet; sed magis gratiarum actio”
The meaning of the words of St. Paul refers, then, precisely and specifically the need for the early followers of Jesus to stay away from these vices and the use of improper or unsuitable phrases.
However, once removed from that context, the "nec nominetur" takes on a more general value, or better, several values and meanings that silence imposed the material silence or the mental reservation or real disgust for make something that is rejected, or the desire not to know the truth.
Its significant nuances can go, then, from the conspiratorial “let it not be cited” "to the recommended "do not mention it", "do not name it to me" or the more imperative "better not to stir it." .
In any case it is the silence that seems to deny or attempt to deny the reality of what everyone knows otherwise because the knowledge of the matter is the circumstantial prerequisite for "nomination".
The phrase, of very specific meaning in the text of St. Paul, is enriched, then, in its nuances depending on the context in which it is used, but all agree on the refusal of recognize (re-learn) what is already known.