How do the page position markers work?

They are the coordinates of each page in the poster. The notation is similar to which is used to refer to cells in everyone's favorite software, Microsoft Excel. Letters mark the column so that they go from A to Z, which is followed by AA and AB. After AZ comes BA, BB and BC and so on. Numbers mark the rows. For example, the paper marked with D7 goes to the fourth column and seventh row.

Assemble the poster like this:

Position marker may overlap rasterbated area depending on dot and page size. It is about 2mm high.