• Specification Format
    • Drawing Format
    • Application Data Sheet
    • Signature Requirements
    • Micro Entity Certification
  • The specification, including the abstract and claims, must be written in English and have lines that are 1.5 or double-spaced in a single column of text
  • Written on only one side in portrait orientation
  • 8.5 by 11 inches with all margins of at least ¾ inches except for a left side margin of at least 1 inch
  • Clearly typewritten in non-script font (e.g., Arial, Times New Roman, or Courier, preferably with a font size of 12), without shading, on white paper
  • The application pages must be numbered consecutively (centrally located above or below the text) starting with page one
  • Drawing figures should not be contained within the specification



  • Title of the Invention (short and specific)
  • Most common applicable sections
  • Claims (on a separate sheet)
  • Abstract (less than 150 words, one paragraph, on separate sheet)

How to file a substitute specification

3 Required Parts of the Submissions

  1. Marked-up copy with markings showing all the changes relative to the immediate prior version of the specification of record
  2. Clean copy (without markings)
  3. Signed statement that the substitute specification contains no new matter


The ENTIRE specification is required for the marked-up and clean copies, not just the amended portion.

Marked up vs. clean copy

Marked up copy:

  • A version that shows ALL changes to the most recent specification of record with markings.
  • Additions of text are underlined.
  • Deletions of text are shown by strike-through, except double brackets

Clean copy:

  • A version that includes ALL changes to the most recent specification of record without markings.

Drawings: Required if necessary to understand the subject matter to be patented

  • A drawing necessary to understand the invention cannot be introduced after the filing date.

Common mistakes found during OPAP drawing review:

  • Line quality that is too light to be reproduced
  • Missing lead lines
  • Excessive text or text that is not in English
  • Paper format
  • Incorrectly labeled figures
  • Photographs that are illegible after scanning
  • Color drawings without a petition
  • Each figure described in the brief description of the drawings must correspond to a separately-labeled drawing figure