The provisions of this section shall apply at all meetings of the City Council.  All amendments shall be considered in the order in which they are moved.  When a proposed amendment is under consideration, a motion to amend the same may be made. No further amendment to such second amendments shall be in order, but when an amendment to an amendment is under consideration a substitute for the whole matter may be received.  No proposition on a subject different from the one under consideration shall be received under color of a substituted.
('84 Code, § 2-16)