PCT Newsletter 05/2023: Practical Advice

WARNING: Although the information which follows was correct at the time of original publication in the PCT Newsletter, some information may no longer be applicable; for example, amendments may have been made to the PCT Regulations and Administrative Instructions, as well as to PCT Forms, since the PCT Newsletter concerned was published; changes to certain fees and references to certain publications may no longer be valid. Wherever there is a reference to a PCT Rule, please check carefully whether the Rule in force at the date of publication of the advice has since been amended.

Rectification of an obvious mistake during the international phase

Q: I have noticed a typographical error in the description of a PCT application I submitted several months ago in which the word 'water' was incorrectly indicated as 'wafer'. Can we correct it before publication and if so, to which authority should such a request be submitted?

A: You may request the rectification of the mistake under PCT Rule 91, which states that an "obvious mistake in the international application or another document submitted by the applicant may be rectified in accordance with this Rule if the applicant so requests." However, please note that the request for rectification must be submitted within 26 months from the priority date (PCT Rule 91.2) and that certain criteria must be met.

The authority to which a request for rectification of an obvious mistake should be submitted depends on which part of the application the mistake is in:

As your mistake is in the description, you will need to submit a request for rectification to the International Searching Authority.

The competent Authority authorizes the rectification of the mistake if, and only if, as at the applicable date under PCT Rule 91.1(f) (the international filing date or, if the mistake is in a document other than the international application as filed, the date on which the document was submitted), it is obvious to the competent authority that:

• something other than what appears in the document concerned was intended; and
• nothing other than the proposed rectification could have been intended. (PCT Rule 91.1)

An error such as a linguistic error, grammatical error or spelling error can, consequently, be requested for rectification providing that it would not change the meaning of the disclosure. Mistakes in a chemical or mathematical formula, for example, would not generally be rectifiable unless the correct formula was common knowledge or has been used in other places of the application.

In many cases, the first criterion is easier to meet than the second one. If, for instance, there was an equation "1+2=5" in the description where it should have been "1+2=3", even if the applicant can convince the competent Authority that it was a mistake and something other than "1+2=5" was intended, it is still not sufficient and it has to be shown that nothing other than "1+2=3" was intended. In other words, it has to be obvious that "3+2=5", "1+4=5", or any other possibility was not intended.

Another example might be where a drawing is blurred and therefore not readable. Even if the applicant can show that the drawing was blurred due to a mistake, it would be very difficult to convince the competent Authority that nothing other than the clear drawing now submitted was originally intended to be submitted as the drawing.

It should be noted that, for a mistake in the description, claims or drawings, the decision of the competent authority on the rectification will be made only on the basis of the description, claims and drawings (PCT Rule 91.1(d)), and therefore information in the priority document will not be taken into account. However, in the case of a mistake in the request, the competent Authority, which would be the receiving Office, can take into account any priority document in respect of the international application that is available to the authority (PCT Rule 91.1(e)).

Consequently, in your case, it has to be obvious to the International Searching Authority from the description, claims and drawings as originally filed that "wafer" in the description was a mistake and nothing other than "water" was intended.

For information, mistakes which cannot be rectified under PCT Rule 91 (PCT Rule 91.1(g)) include:

• missing sheets or elements of the international application referred to in Article 3(2) (request, description, claims, drawings) (please refer to PCT Rule 20.3 to 20.8);
• a mistake in the abstract (please refer to PCT Rule 38.3);
• a mistake in an amendment under Article 19, unless the International Preliminary Examining Authority is competent; or
• a mistake in a priority claim which would cause a change in the priority date.

Please ensure that your requests for rectification reach the competent authority within 26 months from the priority date. Your letter must specify the mistake to be rectified, the proposed rectification together with a replacement sheet, and you may, if you choose, include a brief explanation (PCT Rule 26.4 applies to the manner in which the proposed rectification should be indicated).

Depending on the competent authority, it may be possible for you to submit the request for rectification via ePCT by selecting the recipient and then using the Action "Upload Documents" (there is no specific Action in ePCT related to the rectification of obvious mistakes - please refer to /en/web/epct/learnmore?N=1006 for more information).

If your request for rectification is accepted, the competent authority will notify the IB and provide it with any rectified sheet for publication. If the rectified sheet is received by the IB after technical preparations for publication have been completed, the IB will publish a statement reflecting the rectifications, together with the approved replacement sheets, the letter requesting the rectification and the revised version of the front page (PCT Rule 48.2(i)).

A designated Office is not obliged to take the rectification of an obvious mistake into account if it has already begun the processing or examination of the international application prior to the date on which it is notified under Rule 91.3(a) of the authorization of the rectification by the competent authority.

It may also disregard a rectification if it finds that it would not have authorized the rectification under Rule 91.1 if it had been the competent authority, but it must give the applicant the opportunity to make observations (PCT Rule 91.3(f)).

Please note that even if you have missed the opportunity to rectify a mistake in the description, claims or drawings during the international phase, you have an opportunity to amend them before each designated Office, and therefore you can try to correct the mistake in the description, claims or drawings during the national phase, provided that the amendment meets requirements under the national law (PCT Article 28).

For further information on requests for rectification of obvious mistakes, please refer to the PCT Applicant's Guide, International Phase, paragraphs 11.033 to 11.044 at:

/pct/guide/en/gdvol1/pdf/gdvol1.pdf