The district boundaries are either streets or alleys, unless otherwise shown, and where the indicated boundaries on said district map are approximately street or alley lines, said streets or alleys shall be construed to be the boundaries of such districts.

Where the district boundaries are not shown to be streets or alleys, and where the property has been or may hereafter be divided into blocks and lots, the district boundaries shall be construed to be lot lines; and where the indicated boundaries on the district map are approximately lot lines, said lot lines shall be construed to be the boundaries of each district, unless said boundaries are otherwise indicated on the map.

Where the property is indicated on the district map as acreage and not subdivided into lots and blocks or where the district boundary lines on the district map shall be determined by the scale contained on such map, and where uncertainty exists, the district boundary line shall be determined by the Commission by written decision. In the event property which is shown as acreage on the district map has been or is subsequently subdivided into lots and blocks by a duly recorded subdivision map and the lot and block arrangement does not conform to that anticipated when the district boundaries were established, or property is resubdivided by a duly recorded subdivision map into district map, the Commission, after notice to the owners of property affected thereby and hearing, as required in Section 62 inclusive, may interpret the district map and make minor readjustments in the district boundaries in such a way as to carry out the intent and purposes of these regulations and conform to the street and lot layout on the ground. Such interpretations or adjustments shall be by written decisions.

Where one symbol is used on the district map to indicate the district classification of an area divided by an alley or alleys, said symbol shall establish the classification of the whole of such area.

A street, alley, railroad right-of-way, watercourse, channel or body of water, included on the district map shall, unless otherwise indicated, be included within the district of adjoining property on either side thereof; and where such street, alley, right-of-way, watercourse, channel or body of water serves as a boundary between two or more different districts, a line mid-way in such street, alley, right-of-way, watercourse, channel or body of water, and extending in the general direction of the long dimension thereof shall be considered the boundary between districts.

In the event a dedicated street or alley shown on the district map is vacated by ordinance, the property formerly in said street or alley shall be included within the district of the adjoining property on either side of the said vacated street or alley. In the event said street or alley was a district boundary between two or more different districts, the new district boundary shall be the former centerline of said vacated street or alley.