Amendments of the drawings are permitted, as well as of the other documents. These amendments may be made at the request of the party concerned or at the request of the EPO. The amendments may concern either clerical errors or more substantial changes.

Amendments to drawings are, in general, subject to the same rules as apply in respect of amendments to other application documents and therefore do not require further analysis here. Reference may be made to III, 16; V, 2; C-VI, 3.3, 4.6, 4.7 and 5; and E-II.

The general rule governing the admissibility of amendments, which the examiner must always bear in mind, is that they must not extend the content of the application as filed, i.e. they must not have the effect of introducing new material.

If drawings which depart substantially from the physical requirements laid down in the Rules are filed in order to establish a particular date of filing or retain a priority date, the Receiving Section will permit such drawings to be amended or replaced so as to provide drawings complying with the Rules, provided that it is clear that no new material is thereby introduced into the application. In view of this proviso, applicants should take care that any "informal" drawings which they file clearly show all the features necessary to illustrate the invention.