1) A "SHTAR" WRITTEN IN PERSIAN
OPINIONS: The Gemara says that a Shtar written in Persian that was given over in front of Jewish witnesses (Edei Mesirah) may be used to collect from "Nechasim Bnei Chorin" but not from "Nechasim Meshubadim."
What type of witnesses signed the Shtar?
(a) RASHI (DH Shtara) explains that Nochrim Hedyotos signed the Shtar. He proves this from the Gemara later (19b) which says that a Shtar signed by Arka'os of Nochrim is valid and may be used to collect even from Meshubadim.
Why may a Shtar signed by Hedyotos be used to collect even from Nechasim Bnei Chorin, if the Mishnah says that only a Shtar signed by Arka'os, and not by Hedyotos, is valid? Rashi explains that since the Edei Mesirah are Jewish, Beis Din may rely on the Shtar.
However, if there are valid Edei Mesirah who can attest to the details of the transaction, why is a Shtar necessary at all? Why should Beis Din need to rely on the signatures of the Hedyotos in the Shtar? The Gemara should say simply that one may collect based on the Jewish witnesses (the Edei Mesirah), and not only may the signatures on the Shtar be ignored, but the entire Shtar itself may be ignored!
The TOSFOS RID asks this question. He answers that the Shtar is necessary because it prevents the borrower from claiming that he already repaid the debt. Although the Shtar does not allow the lender to collect from Nechasim Meshubadim, it does provide proof that the debt has not yet been repaid. (According to the view of the RA'AVAD (Hilchos Malveh v'Loveh 27:1) who maintains that a Shtar which cannot be used to collect from Meshubadim cannot be used to prove that the debt was not repaid, another explanation will need to be given.)
(b) The RI (see TOSFOS, DH Lo Nechleku) rules that the Beraisa mentioned earlier on the Daf disqualifies a Shtar signed by Hedyotos even when there are Jewish Edei Mesirah, according to the Chachamim who argue with Rebbi Akiva. Therefore, the Ri explains that the Persian Shtar discussed by the Gemara was signed by Arka'os. Although it was signed by Arka'os, it may not be used to collect from Nechasim Meshubadim because it does not have a "Kol."
The Ri alters the Girsa of the Gemara later (19b) in order to make it consistent with this ruling. (See ROSH 1:10.)
(c) The ROSH himself explains that the Persian Shtar discussed by the Gemara has no signatures at all. Although the Rabanan disqualified a Persian Shtar on which Hedyotos signed even when there are Jewish Edei Mesirah (because it is "Mezuyaf mi'Tocho"), they did not disqualify a Persian Shtar that has no witnesses signed on it.

11b----------------------------------------11b

2) SIGNATURES OF FOREIGN-SOUNDING NAMES
QUESTIONS: Reish Lakish asked Rebbi Yochanan whether a Get is valid when it has the signatures of witnesses who have names commonly used by Nochrim (and Beis Din does not know whether those signatories are Jewish or not). RASHI explains that Reish Lakish's question was whether Beis Din may accept the Get when there are valid Edei Mesirah, or whether it will be invalid even with Edei Mesirah because it is "Mezuyaf mi'Tocho."
Rebbi Yochanan answers that the only Shtar which the Chachamim permitted, with Edei Mesirah, is a Get with signatures of "Shemos Muvhakim" of Nochrim ("Lukus" and "Lus") -- names used exclusively by Nochrim and not by Jews. A Get that has signatures of "Shemos she'Einam Muvhakim" -- names of Nochrim that are not used exclusively by Nochrim but are used by Jews -- is not valid.
(a) Why does Rashi explain that Reish Lakish's question was whether or not the Get is valid because of its Edei Mesirah? The Gemara later cites a Beraisa that states that when a Get is brought from Chutz la'Aretz with foreign names signed on it, it is valid, since most Jews in Chutz la'Aretz have such names. Rashi explains that the Beraisa permits Gitin with foreign names even without Edei Mesirah because we assume that the signatories are Jewish. The Gemara attempts to prove from the Beraisa that even when a Get comes from within Eretz Yisrael with foreign names signed on it, we may assume that the signatories are Jewish.
Why does Rashi here not explain that the reason why Reish Lakish wanted to permit the Get was because we assume that the signatories are Jewish? Why does Rashi explain instead that Reish Lakish's question was whether or not we rely on the Edei Mesirah? (TOSFOS, in fact, explains this way, that Reish Lakish wanted to permit such a Get because we assume that the signatories are Jewish.) (MAHARAM SHIF)
(b) According to Rashi, the Gemara is questioning whether we permit a Get with names of Nochrim which are Shemos she'Einam Muvhakim because of the Edei Mesirah (according to the opinion of Rebbi Shimon). Why is the Gemara questioning whether we accept Shemos she'Einam Muvhakim according to Rebbi Shimon? The Gemara earlier (10b) takes it for granted that Rebbi Shimon does not accept Shemos she'Einam Muvhakim because of the invalidating factor of "Mezuyaf mi'Tocho." (RASHBA, PNEI YEHOSHUA)
(c) Regarding the Beraisa which says that Gitin which come from Chutz la'Aretz with foreign names are valid because most Jews in Chutz la'Aretz have such names, the Gemara concludes that the reasoning of the Beraisa does not apply in Eretz Yisrael, since most Jews in Eretz Yisrael have Jewish names. Rashi writes that since Jews in Eretz Yisrael have Jewish names, if a Get with foreign names is sent from within Eretz Yisrael we must suspect that the signatories are not Jewish, and therefore the Get is invalid even with Edei Mesirah "like the Rabanan of our Mishnah."
Why does Rashi attribute this opinion to the Rabanan of the Mishnah? The names signed on the Get in that case obviously are not Shemos Muvhakim of Nochrim, because Rashi writes that we are uncertain about the identity of the witnesses who signed. In such a case, even Rebbi Shimon of the Mishnah disqualifies a Get with Shemos she'Einam Muvhakim because of "Mezuyaf mi'Tocho" (10b)! (MAHARSHA and others)
ANSWERS:
(a) The reason why Rashi explains that Reish Lakish sought to permit the Get because of the Edei Mesirah is that he wants to explain the context of Rebbi Yochanan's answer to Reish Lakish's question. Rebbi Yochanan answered that we permit a Get with Shemos Muvhakim of Nochrim but not a Get with Shemos she'Einam Muvhakim. If Reish Lakish's question was whether the signatories are assumed to be Jews or Nochrim, Rebbi Yochanan's answer about permitting a Get with signatures of Nochrim with Shemos Muvhakim is entirely unrelated to Reish Lakish's question. Reish Lakish asked only about names that could be Jewish names. Why did Rebbi Yochanan answer that we permit Gitin with Shemos Muvhakim of Nochrim?
Therefore, Rashi explains that Reish Lakish indeed was questioning whether we may rely on Edei Mesirah even when the names signed on the Get are names of Nochrim that are not Muvhakim. Rebbi Yochanan replied that we rely only on foreign-sounding names when they are Shemos Muvhakim.
(b) Although Rebbi Shimon normally does not permit a Get signed with names of Nochrim that are not Muvhakim because of the Pesul of "Mezuyaf mi'Tocho," this Pesul is only a Pesul d'Rabanan. Therefore, when there is a possibility that the witnesses who signed the Get are actually Jewish (and the Get is not Pasul), perhaps we may be lenient since it is only a Safek d'Rabanan. That is why Reish Lakish asked what the Halachah is when the names on the Get are Shemos she'Einam Muvhakim and we do not know whether the witnesses who signed are Jewish or not. (RASHBA, PNEI YEHOSHUA)
(c) The RASHBA explains that Rashi means to say that Rebbi Yochanan and Reish Lakish do not necessary rule like Rebbi Shimon. (After all, the Rabanan argue with Rebbi Shimon, and thus the Halachah should follow their opinion, the opinion of the majority.) Rashi suggests that even the Rabanan -- who invalidate a Get both when it has Shemos Muvhakim and when it has Shemos she'Einam Muvhakim because of the Pesul of "Mezuyaf mi'Tocho" -- might permit the Get in the case of Reish Lakish in which there is only a doubt about whether it is "Mezuyaf mi'Tocho," since the persons signed on the Get might actually be Jews.
The Rashba explains that even names like "Lukus" and "Lus" -- which are Shemos Muvhakim of Nochrim -- do not preclude the possibility that the signatories are really Jews. The Gemara says only that it is very uncommon for Jews to bear such names, but not that it is impossible or unheard of completely.
The MAHARAM SHIF, however, points out that from the context of Rashi's words it seems that Rashi's intention is not to explain why the Get would be valid even according to the Rabanan, but why a Get with Shemos she'Einam Muvhakim would be invalid according to the Rabanan (and only according to the Rabanan). Why should Rashi limit this ruling to the opinion of the Rabanan? Even according to Rebbi Shimon, Safek Nochrim with Shemos she'Einam Muvhakim should invalidate a Get, and Safek Nochrim with Shemos Muvhakim should not!
The MAHARSHA also writes that Rashi seeks to explain the entire Sugya according to the opinion of the Rabanan. The Maharsha explains that the only reason why the Rabanan invalidate a Get with foreign-sounding names signed on it is that we might rely on the Nochrim who signed it to serve as the Edei Mesirah as well. When a Get comes from Medinas ha'Yam, however, it is impossible to use the witnesses who signed it as the Edei Mesirah (since they are out of the country). Therefore, the Rabanan have reason to be more lenient and say that when the names are Shemos Muvhakim the Get is valid, and only when the names are not Muvhakim do they invalidate the Get.
Rebbi Shimon, in contrast, would accept the Get even when the names are Shemos she'Einam Muvhakim. Since Rebbi Yochanan accepted only a Get from far away that was signed with Shemos Muvhakim, Rashi understands that he followed the opinion of the Rabanan.
Another possibility (see MAHARAM SHIF) is that when Rashi writes that a Get with Shemos she'Einam Muvhakim is invalid "like the Rabanan of our Mishnah," he does not refer to the Tana Kama of the Mishnah, but rather to all of the Tana'im of the Mishnah (the "Rabanan" of the Mishnah refers to the Tana Kama as well as Rebbi Shimon)! Rashi means out that one should not think that the Gemara here follows a minority opinion. Rather, the Gemara's ruling is accepted by all of the Tana'im of the Mishnah (to the exclusion of the Tana'im of the Beraisa).
Rashi follows his own view as expressed earlier (10b, DH Teni Chutz), where he explains that the Tana Kama of the Mishnah here follows the view of Rebbi Meir, that Edei Chasimah Kartei. Hence, there is no Tana in the Mishnah who would say that according to Rebbi Elazar a Get with Shemos Muvhakim is invalid. All of the Tana'im in the Mishnah agree that a Get with Shemos Muvhakim is valid (with Edei Mesirah) according to Rebbi Elazar. The Tana'im of the Beraisa (9b), however, argue about whether Rebbi Elazar would permit a Get with Shemos she'Einam Muvhakim, as the Gemara there explained.