Waiver. A letter of waiver from minor application procedure for a certificate of appropriateness is available for the applicant who complies with accepted standards, colors or techniques to be used with respect to the maintenance and upkeep, painting, replacing, or repairing of an applicable structure. Said standards, colors and techniques shall be on file with the Secretary of the Historic Commission. A letter defining the requested waiver which indicates the property in question and the particular maintenance, upkeep, painting, replacing or repairing sought to be done, shall be available without charge from the office of the Chairman or Secretary of the Historic Commission. Such letter shall have an indefinite duration, thus eliminating the need for successive exemption letters for the same type of maintenance, upkeep, painting, replacing or repairing.