A taxpayer liaison officer (TLO) must be appointed by the appraisal district board of directors in counties with a population of more than 120,000. The TLO is the appraisal district officer primarily responsible for providing assistance to taxpayers for the district, administering public access functions, resolving disputes not involving matters that may be the subject of a protest and compiling a list of comments, complaints and suggestions related to the fairness and efficiency of the ARB.