Ordinances which are compilations of rules and regulations or codes may be enacted by reference to such compilation or code and may be published by title in a condensed summary of the contents thereof. Provided that when such compilations or codes are passed or enacted by reference, or are published in summary form such compilation or code so enacted need not be enrolled in the book or ordinances, but a copy shall be authenticated by the signatures of the Mayor and the City Clerk and filed and kept in the office of the City Clerk. The City Clerk shall keep copies of all such compilations or codes for distribution or sale at their approximate cost.