100. IDENTIFICATION 1. Poles, towers, and other supporting structures shall be constructed, located, marked or numbered so as to facilitate identification thereof by employees authorized to work thereon. Date of installation or year of manufacture of each such structure shall be recorded by the owner by a year nail driven into the pole, or by other appropriate means or records.2. Where two or more utilities maintain poles, towers, or other supporting structures within the same municipality, each utility shall, within a reasonable time after the adoption of these rules, mark each such pole, tower, or other supporting structure with the initials of its name, abbreviation of its name, corporate symbol, or other distinguishing mark by which the owner of each structure may be readily and definitely determined.3. In the case of two or more utilities jointly owning any such pole, tower, or other supporting structure, the distinguishing mark of each utility shall be placed thereon.4. In the case of poles, towers, or other structures erected upon private rights of way or on public ways, when of such character that the construction may be deemed to be a through line, marks shall be affixed more frequently than to every tenth structure.5. The requirements herein shall apply to all future erected structures and to all changes in ownership and, as far as may be practicable, to all existing structures.6. Every utility shall file with the Commission, in duplicate, a statement showing (a) the initials, abbreviations of name, corporate symbol or distinguishing mark used by it for the purposes herein specified, (b) the means of marking to be employed, and (c) the method intended to be followed in marking for identification structures upon through lines.