Sign where there is no signature. AdobePhotoshop, abbreviated as "PS" or "P", is an image processing software developed and published by AdobeSystems. Photoshop mainly deals with digital images composed of pixels. With its numerous editing and drawing tools, you can edit pictures effectively. Ps has many functions, including pictures, graphics, text, video, publishing and so on. P signature is to sign where you have not signed. If P-sign refers to irregular places such as P-sign contracts, it may violate the law. To sign is to write one's name, especially to express agreement, recognition, responsibility or obligation.