A page of a printed product having a plurality of information fields arranged in different printed columns is provided. At least one perforated line, extending parallel to the height of the page, is generated in the page between at least two printed columns. The at least one perforated line is formed over the entire height of the page. At least one printed column, along with its at least one information field, can be completely separated from the remaining part of the page via a separation process to be performed along a single such perforated line. The perforated line to be used to execute the separation process extends through a pictogram that is situated along both sides of this perforated line. The pictogram visualizes the position of this perforated line. A longitudinal perforation device for a web-fed rotary printing press can be used to produce this page and has at least one perforating blade for generating the perforated line. The longitudinal perforation device is configured as an autonomous module. That module can be used in different places in the same web-fed rotary printing press or at different times in different web-fed rotary printing presses.