225 ILCS 325/14
Every professional engineer shall have a reproducible seal , which may be computer generated, the imprint of which shall contain the name of the professional engineer, the professional engineer's license number, and the words "Licensed Professional Engineer of Illinois". Any reproducible stamp heretofore authorized under the laws of this State for use by a professional engineer, including those with the words "Registered Professional Engineer of Illinois", shall serve the same purpose as the seal provided for by this Act. The engineer shall be responsible for his or her seal and signature as defined by rule. When technical submissions are prepared utilizing a computer or other electronic means, the seal may be generated by the computer. The licensee may provide, at his or her sole discretion, an original signature in the licensee's handwriting, a scanned copy of the technical submission bearing an original signature, or a signature generated by a computer.
The use of a professional engineer's seal on technical submissions constitutes a representation by the professional engineer that the work has been prepared by or under the personal supervision of the professional engineer or developed in conjunction with the use of accepted engineering standards. The use of the seal further represents that the work has been prepared and administered in accordance with the standards of reasonable professional skill and diligence.
225 ILCS 325/14