In summary, the term 'domestic support obligation' includes child support, alimony, or other support payment, and can include payments for housing, health insurance or other costs paid on behalf of a spouse or ex-spouse. If payments are owed and in arrears then the 'domestic support obligation may also include interest and the interest is non-dischargeable as well.
It is very important when preparing a Chapter 7 Bankruptcy to be aware that these debts will not be discharged, i.e. will still be owed after the bankruptcy.
It is likewise very important when preparing a Chapter 13 Bankruptcy to be include the 'domestic support obligation' in the Chapter 13 plan as a priority debt and to be clear about how arrears will be paid versus how the ongoing payment reduces the filer's available income. If these issues are not addressed specifically, the Bankruptcy Court may find that the Plan is not binding against your ex-spouse as was the case in In re Owen, 2009 WL 693161 (Bky.E.D.Tenn. March 13, 2009). For an excellent explanation of what happened in that case check out the following article on the Bankrutpcy Law Network: "Stealth" Plan Provisions: Confirmation of Chapter 13 Plan Did not Alter Domestic Support Obligation".