If the European patent application does not comply with the requirements of Rule 57(a) to Rule 57(d), Rule 57(h) and Rule 57(i), the European Patent Office shall inform the applicant accordingly and invite him to correct the deficiencies noted within two months. The description, claims and drawings may be amended only to an extent sufficient to remedy such deficiencies.
Source: http://www.epo.org/law-practice/legal-texts/html/epc/2016/e/r58.html
Date retrieved: 17 May 2021