2.2 Allowability 

For a correction of linguistic errors, errors of transcription and mistakes in any document filed with the EPO to be allowable, the following requirements must be met (G 1/12):

(i)The correction must introduce what was originally intended. The possibility of correction cannot be used to enable a person to give effect to a change of mind or development of plans. It is the party's actual rather than ostensible intention which must be considered. 

(ii)Where the original intention is not immediately apparent, the requester bears the burden of proof, which must be a heavy one. 

(iii)The error to be remedied may be an incorrect statement or an omission. 

(iv)The request for correction must be filed without undue delay. 

However, correction of errors in the description, claims and drawings is a special form of amendment and is bound by Art. 123(2) (G 2/95; see also H‑VI, 2.2.1). These errors can be corrected as set out below.

If a request for correction under Rule 139 is allowed during opposition, the correction will be published as part of the publication of the patent as amended.