Good question. If you have a written check list from your former landlord at move out that all was fine with the former rental and now there are claims that there was some missed damage that your former landlord wants you to pay for, I would do the following:1. write the former landlord a letter stating that he or she signed a check list at move out that all was fine. Keep a copy of the letter for future reference if need be.2. advise the landlord that the third party debt collection agency that is bothering you about the unliquidated claim could be in violation of federal and state unfair debt collection practices and that attempts to contact you must stop.3. if your are still being pestered by the landlord and/or the third party debt collection agency, you should consult an attorney who practices landlord tenant law.The good part about what you have written is that you have a move out check list showing that things seemingly were fine with the rental's condition when you moved out. Make copies of that document for safe keeping.