Shulchan Aruch Chapter 591:
How the Quiet Musaf (מוסף, additional service) is Performed (8 paragraphs)
Note: The REMA is in brackets 
1. The congregation should pray quietly the Musaf prayer of nine blessings and the Chazzan should also pray with them silently.
2. The common custom of all Sephardim is to not mention the verses relating to the Musaf sacrifice at all. [The common custom of the Ashkenazim and in these areas is to say the verses relating to the Musaf sacrifice of Rosh Hashanah but we don’t say the verses of the Musaf sacrifice on Rosh Chodesh (that falls out on R.H.) but we say “מלבד עולת החדשׁ ומנחתה ועולת התמיד וכו׳” “ושׁני שׂעירים לכפר ושׁני תמידין כהלכתן” and we also the Musaf sacrifices of the day of atonement (on R.H.).]
3. One must say the Musaf offerings of the day of atonement in order that it should also cover the Musaf offerings of Rosh Chodesh. This should also be said on the second day.
4. We say ten verses of kingship (מלכיות), ten of remembrance (זכרונות), and ten relating to the Shofer (שׁופרות) in every blessing. Three of them are verses from the Torah, three are from the כתובים (holly writings), three are from the Prophets and (the last) one is from the Torah. If one wants to add on to these ten, he may do so. [However, if one did not begin any verse but said instead “and in your Torah the following is written ... (ובתורתך כתוב לאמר)” you are Yotzai .]
5. We do not say anything about the punishment of Israel in the verses of kingship, remembrance and Shofrot. And we don’t say a verse for the remembrance of an individual (זכרונות שׁל יחיד).
6. Some protest over the custom to complete the verses of Shofrot with the verse,“וביום שׂמחתכם” (“And on you joyous days...”) since it does not mention “Shofer” but instead says “חצוצרות”. But the רא׳שׁ and the ר׳ן write to fulfill the custom.
7. “And the offering of Isaac you should remember for his seed.” (“ועקידת יצחק היום לזרעו תזכור”) is the most widely used version. But the careful ones say “and the offering of Isaac you should remember for the seed of Jacob” (“לזרע יעקב תזכור”). This is a faulty change since the Elders made a mistake in Berachot so this is nothing but a mistake (so you shouldn’t change it to the seed of Jacob). [Plus we sayעלינו & ומלוךand the Chazzan adds on אוחילה and other poems, every place according to its custom.]
8. You should not say the silent Musaf prayer of Rosh Hashanah until after three daylight hours .
Translated by Jay Dinovitser www.shulchanarach.com
 M.B: In other words, you don’t have to say the entire verse but could say part of the verse with the introduction “and it says in your Torah ...”. However, he writes that you should say the entire verse anyways, since this is preferred.
 I am unsure of the literal meaning of this verse. The general explanation as explained by the Mishna Brura is that when you say “his seed” you seem to be including Esau, which is also Isaac’s seed although the authorities hold that “the seed of Isaac” only refers to Jacob because he is considered Isaac’s seed. Nonetheless, it is better to be more specific. Other opinions hold that “the seed of Isaac” only can refer to Jacob so there is no need to change it. Both have whom to rely on and one should go according to his custom since both are OK.
 These are not equivalent to an hour but vary each day depending on sunrise and sunset times. Take (Sunrise-Sunset)/12 to get one daylight hour. The reason relates to the time Hashem judges the world (see M.B.)