Includes facilities that play the negotiator or mediator between the parties to the contract in the business operations of convergence of views, as well as the conclusion of contracts of sale or purchase either on behalf of the personal account of others through the holding of the so-called intermediate contract in return for commission or remuneration from a third party, or the conclusion of contracts of sale or purchase personal name on the face of the independence, but dealing be credited to others through two decades, one between the dealer and the other between them and the client in return for getting a commission or remuneration from a client, these installations are not permitted the practice of mediation activity in the sale and purchase of real estate.