1. Substitute sheets and rectified sheets 

Replacement pages or sheets, filed in response to an invitation by the receiving Office to correct defects in the international application, are deemed to be part of the international application "as originally filed". These sheets are identified with a stamp "SUBSTITUTE SHEET (RULE 26)" (see GL/PCT‑EPO H‑IV, 1). Also, replacement pages or sheets for rectification of obvious mistakes under Rule 91 are deemed to be part of the international application "as originally filed". These sheets are identified with "RECTIFIED SHEET (RULE 91.1)" (see GL/PCT‑EPO H‑IV, 2.2).

See GL/PCT‑EPO H‑IV, 2, for the procedure to follow if the rectified sheets contain added subject-matter.