We landlords are in the same quandary as employers when we’re called upon to give recommendations.  On the one hand, we want to get honest recommendations from somebody else when we are checking on an applicant and trying to decide whether to initiate a relationship; on the other hand, we are reluctant to give honest recommendations ourselves because we are afraid that we might be sued for saying the wrong thing.

You can’t go wrong by verifying a tenant’s dates of occupancy, his address, his rent, his payment history and the circumstances of his/her departure when called upon to do so.  That is not a recommendation - that is information which another landlord may draw his/her own conclusions from in determining whether to rent to your tenant. That is information and so long as it is accurate, it would be difficult, if not impossible, to refute in a court of law.

Go ahead and supply a fellow landlord with information which you can prove, information which you would like to receive if you were checking out an applicant.  Do not say things about a tenant that you cannot or are unable to prove.