What is Rome talking about? The "Tetragrammaton". Confused? We're talking about the four Hebrew letters yod, heh, vav, and heh (יהוה) transliterated in English as "YHWH", and found in some translations of the Old Testament as well as the occasional hymn as "Yahweh". "Tetragrammaton" is a Greek word meaning "four letters", as in the 4 letters used to name God.
In books of Scripture written in Hebrew, the name is certainly written, but never pronounced phonetically. Instead, the word "Adonai" ("God") is substituted, or even the words "Ha Shem" (literally, "The Name") are used. For Jews, even to say the proper name of God would be a violation of the third commandment (or second commandment to Christians), taking God's name in vain. The only time it was used in Judaism was once per year by the High Priest during Yom Kippur, when he alone had the privilege of pronouncing God's authentic name while offering prayers of atonement on behalf of the people.
What a great chance this gives us to reflect on our use of the word, "God", in our culture and in our own vocabulary. Yes, lots of people come to confession and tell us that they've "used God's name in vain" (which is a sterilized way of saying they have a foul mouth), but in reality, most obscenities do not use the word, God, except for the one that most resembles, "Goshdarnit!" (use your imagination). How many times do we begin a sentence with, "O my God, that was the best (food) I've ever eaten!", or, "I swear to God, I saw (proper name) at the mall with (another proper name)." This is starting to look like Mad Libs, no? You get the idea.
So what does this mean? First of all, directive one says that the word "YHWH" is not to be used in liturgical celebrations. This would affect hymns like "You are Near", and, "Sing a New Song" (which has the line in the first verse about Yahweh's people dancing for joy). Honestly, I'm not shedding any tears in putting those songs out to pasture. The second directive says that in future translations of Scripture into vernacular languages, the word YHWH be translated as "God". It's hard to say what this will affect in the future, but looking to the past, I believe it is the New Jerusalem Bible that used "Yahweh" in translations of the Psalms. In short, words like "God" or "Lord" should be used, rather than God's proper name.