Sabbatical abolishes loans at the End of the Sabbatical year: Shabbat 148b
Whether this abolition applies outside of Israel: Kiddushin 38b
Whether this abolition applies even in an era when land in Israel is not rested for Shemitah: Kiddushin 38b
Whether this abolition applies to loans which were originally scheduled to terminate after the Shemitah year: Makkot 3a-b
Differentiating between Rosh HaShanah where the Month of Elul should have had 30 days and where it should not have: Shabbat 148b
For the Sabbatical to abolish a tab which was run up on Rosh HaShanah [of the 8th year] itself: Shabbat 148b
Abolition of specific kinds of debts
Abolition of a debt incurred on the condition, "That the Sabbatical Year should not abolish this debt," or "That you should not abolish this debt in the Sabbatical Year": Makkot 3b
At what point general fines may be abolished: Gittin 18a
Abolition of a loan which has an outstanding collateral held: Bava Metzia 48b-49a; Makkot 3b
Does shemitah nullify a loan despite its collateral, in a region where the borrower has the recognized right to pay back the debt, reclaiming the collateral, at any time [atra d'misalki]: Bava Metzia 67b
Abolition of a loan for which the document has been transferred to a court for collection: Makkot 3b
Attempts to Repay
The lender must say "I Abolish the Debt" if the borrower attempts reimbursal: Shabbat 148b