Image forming system that forms adjustment pattern for adjusting image forming condition

An image forming system, comprising:

• an image forming unit configured to form an image on a sheet;
• a reader configured to optically read the sheet on which the image has been formed by the image forming unit, and output read image data indicating a read image;
• at least one memory storing instructions;
• and
• one or more processors configured to execute the instructions,
• wherein, based on image data, the image forming unit forms a user image and an adjustment pattern for adjusting an image forming condition, wherein the user image includes a region inside trimming positions of the sheet and includes a content image outside the trimming positions, and wherein the adjustment pattern is outside the trimming positions, and
• wherein execution of the instructions causes the one or more processors to:
• adjust the image forming condition at a time of image formation by the image forming unit, and
• in a case where a formation region of the content image and at least a part of a formation region of the adjustment pattern overlap, determine whether the formation region of the adjustment pattern can be moved so that the formation region of the content image and the formation region of the adjustment pattern do not overlap, and, in a case where the formation region of the adjustment pattern has been determined to be movable, move the formation region of the adjustment pattern so that the formation region of the content image and the formation region of the adjustment pattern do not overlap.