For zoning lots utilizing the provisions of Section 23-72, inclusive, the yard regulations shall be modified as follows:

1. in R5 Districts without a letter suffix, the front yard regulations shall be modified as follows: a front yard shall be provided with a depth of not less than five feet provided that, for corner lots, one front yard with a depth of not less than 10 feet is required; 
2. in R5 Districts and R6 Districts without a letter suffix, the rear yard regulations shall be modified to require a rear yard with a depth of not less than 20 feet at every rear lot line on any zoning lot.