Section 191. A client or employer may retain or employ a state-certified general real estate appraiser, state-certified residential real estate appraiser or state-licensed real estate appraiser to act as a disinterested third party in rendering an unbiased estimate of value or analysis. A client or employer may also retain or employ a state-certified general real estate appraiser, state-certified residential real estate appraiser or state-licensed real estate appraiser to provide specialized services to facilitate the client's or employer's objectives. In either case, the appraiser and the appraisal report must comply with the provision hereof.