Registration numbers shall be assigned by the City Manager to a particular taxicab, described by its motor number. The licensee shall affix one of the tags containing the registration number to each of his taxicabs, in a conspicuous place, to be designated by the Chief of Police. No licensee or taxicab driver shall operate or use any taxicab as such unless the license tag is affixed to the taxicab as hereinbefore provided, or operate or use any taxicab as such with any license tag other than the tag originally assigned to that taxicab, or change the tags from one taxicab to another. (1947 Code, Sec. 8-65.)