How does OPAP handle applications with informal drawings?

When an application is filed with informal drawings, the Office of Patent Application Processing (OPAP) will review the drawings to determine if they can be used for publication purposes. If the drawings are not acceptable for publication purposes, OPAP will object to the drawings and require corrected drawings within a set time period, usually two months. This objection does not affect the filing date of the application, and applicants can correct the drawings later in the examination process if needed.