Whether a document complies with Art. 108 EPC, third sentence, is considered to depend on its substance and not upon its heading or form (T 145/88, OJ 1991, 251, where the document headed "Statement of Grounds" was found not to contain even the minimum of reasoning and thus was not a statement of grounds at all). The mere existence of some argumentation and carrying the heading "Statement of the Grounds of Appeal" or "Grounds" does not automatically pass the threshold of Art. 108 EPC, even if clearly relating to the substance of the impugned decision (T 1581/08, referring to T 145/88). The board went on to point out that sufficiency is also not a question of volume. There is no minimum requirement as to the length or the fullness of detail of the argumentation which is necessary for an admissible appeal. In this context a distinction is to be drawn between insufficiency for the purposes of admissibility and insufficiency as far as the persuasiveness of the grounds is concerned which – if the arguments are not convincing – results in the dismissal of the appeal (see T 922/05 and below). See also e.g. T 23/03 and T 613/07.

The board in T 74/12 pointed out that R. 99(2) EPC did not require a case number to be indicated in the statement of grounds of appeal. That logically implied that an appeal could not be found inadmissible simply because the case number was missing, as only the law, viz. the EPC and its implementing regulations, could define the conditions for taking certain procedural steps and the consequences to be expected if those steps were not taken. A procedural principle stated that rights or a means of redress could be lost only if such a consequence was clearly and precisely prescribed.