Halakhah for Makkot 40:15

From the laws of the commandment - like that which they, may their memory, said (Makkot 20b) that one who makes a marking is liable one [distinct set of] lashes for each and every marking, and that is when they warned him on it about each and every one, and [that] one who makes one marking for five dead is liable for five [sets of] lashes; and the rest of its details - are at the end of Tractate Makkot. And Rambam, may his memory be blessed, wrote (Mishneh Torah, Laws of Foreign Worship and Customs of the Nations 12:14) that they, may their memory be blessed, also expounded that included in this warning (negative commandment) is that there not be two courts in one city [whereby] one follows one custom and the other follows another custom, as this causes disagreement; and the expression, "do not gash yourselves" (titgodedu) is meaning to say, do not create many groupings (agudot, agudot), which means to say that they be differing with one another. [But] from my teacher, God protect him, I have learned that this prohibition is only with one group, some of which differs with [the rest] - and they are equal in wisdom. [In such a case,] it is forbidden for each of their factions to follow its [own] words, as this creates disagreement among them. Rather, they should give and take much among themselves about the thing until they all agree to one opinion. And if it is impossible like this, they should all follow the words of those that are stringent, if the disagreement is about something from Torah writ. But [this prohibition] was not said about two courts that disagree - and they are equal in wisdom. And they brought a proof from the story in Tractate Chullin (it should read Avodah Zarah 40a) - as they said there, "[They] took out the shofar of [Rav to make a proclamation] and forbade it, and [in the same town, they] took out the shofar of [Shmuel to make a proclamation] and permitted it."