Allowing testimony by a single witness, to establish the [im-]permissibility of a disputed item: Gittin 2b, 3a
The above is not so, for cases involving adulterous/incestuous relationships: Gittin 2b, 3a
Amatla [אמתלא] - An Excuse, Explaining a [False] Statement
Explain why a woman said she was married, falsely: Ketuvot 22a
Explain why a woman said she was Menstruating, falsely: Ketuvot 22a-b
BeYado [בידו] - Credibility Where the Truth is Under the Testifier's Control
Believing a father that his son is a Kohen, to eat Terumah, but not for Marriage: Ketuvot 25b
Believing that a house was checked for Leaven before Pesach: Pesachim 4a-b [See Tos.]
Worrying about "Favor-Traders [גומלין]" Among Witnesses Aiding Each Others' Cases
Testimony on his friend's status as a kohen: Ketuvot 23b-24a
Testimony claiming his friend's produce was already tithed: Ketuvot 24a, 56b
Above, if it is clear that he has come to sell his own produce: Ketuvot 24a-b, 56b
The one who forbade X, permitted X [הפה שאסר הוא הפה שהתיר]
For Different Levels of Personal Liability in the Testimony: Ketuvot 23b-24a
Source for this principle, in Pesukim or in Logic: Ketuvot 22a
If there are other Witnesses for the Prohibition Part: Ketuvot 17b-18a, 18b, 19b, 22a
What if testimony was accepted on the basis of "He who Forbade it Permitted It," and then witnesses came to Forbid it: Ketuvot 22a
"Your father owned this field, and sold it to me": Ketuvot 15b-16a, 17b
"You sold this field to me": Ketuvot 17b
"I borrowed money from you, and paid it back": Ketuvot 18a
"I borrowed money from your father, and paid part back": Ketuvot 18a
"Those are our signatures, but our Testimony was Invalid": Ketuvot 18b
Verifiers recognize the Witnesses's signatures, but say the Testimony was Invalid: Ketuvot 19b
"I was married, and am now divorced": Ketuvot 22a
"I was captured, but I was not Nivelet": Ketuvot 22a
Mah Li LeShaker [מה לי לשקר] - Why would I lie?
Where there are Witnesses: Ketuvot 27b
If a woman says she didn't hide from the invading soldiers, nor was she slept with: Ketuvot 27a-b
If a leaser says he took a hired animal where he shouldn't have, but the damage didn't come from an expected danger: Ketuvot 27b
Maysi'ach Lefi Tumo [מסיח לפי תומו] - Speaking without Knowledge of the Speech's Effect
Testimony that a man's brother is a Levi: Ketuvot 25b-26a
Testimony that a man is a Kohen, because he says he ate Terumah: Ketuvot 26a
Testimony that a man's mother was captured but not Niv'eles: Ketuvot 27b
Rav Pappa allowed a bill written in a Persian Court, by calling in two separate Kutim to read it to him, unaware of the ramifications of their testimony: Gittin 19b
Migo [מיגו] - Believe a litigant who makes claim X, becaue they could have made a claim Y which would have been better for them
One Migo can be used on a case, but two can't be combined: Bava Metzia 9b
A Migo argument in which one says, "If I were a sinner, I could have committed an illegal act": Keritot 11b, 12a [and see Tosafot Bava Kama 40b]
Believing a woman for her ketubah rights when she explains how she lost her betulim, because she could have made a better claim for herself: Ketuvot 12b-13a, 15b-16b
Believing someone regarding his rights to a particular property, where he created the doubt about his own rights in the first place: Ketuvot 15b-16b
Milta De'Avida Le'Igluyay [מילתא דעבידא לאיגלויי] - A Case where the Truth Will be Known
That the court declared the New Month: Rosh HaShanah 22b
That a husband died: Yevamot 115a
Shavyah ANafsheih Chaticha De'Issura [שויה אנפשיה חתיכה דאיסורא] - Forbidding an item to one's self (alone)]
Testimony that one's own wife was adulterous: Ketuvot 9a-b
Testimony of a woman that she is married: Ketuvot 22a
Testimony of a woman that she was captured and slept with, vs. One Witness's Testimony: Ketuvot 23b
If a woman says, "I was captured, but I was not sexually abused," and there are witnesses that she was a captive: Ketuvot 13b
If a woman said she was a virgin at the time of kiddushin, and then she is not a virgin at the wedding, but she says she lost it in a non-sexual way: Ketuvot 11b, 13a
If a woman said she was a virgin at the time of kiddushin, and then she is not a virgin at the wedding, and she says she was raped after kiddushin: Ketuvot 11b, 12b