ANSI X9.100-140-2018 establishes the construction, layout, data elements, data content, and printing specifications for Image Replacement Documents (IRD). An IRD is a substitute image copy of a check or a replacement for a previous IRD that includes a machine readable MICR line. An IRD that conforms to this standard and meets the requirements of a Substitute Check within Regulation CC is considered the practical and legal equivalent of the original paper check or of a previous IRD. This standard does not address operational, implementation, or settlement issues. These issues may include but are not limited to: the use of security features that are available after imaging, image compression, conversion methods, and IRD printing techniques. The informative annexes attached to this standard provide information that may prove useful to those planning on implementing the standard.