In this revocation appeal the Board had to decide on the admissibility of the main request (and several other requests). The relevant facts are mentioned in the decision.
*** Translation of the German original ***
 During the oral proceedings (OPs) the patent proprietor declared that, in view of the fact that the Board had invoked the rules of procedure and refused to admit its “main request” and its “auxiliary requests 1 to 8” of May 29, 2013, […], it wanted to revert to its request of December 4, 2008, which it had submitted before the OD and have it considered as its main request. […]
However, the fax of the patent proprietor which [the EPO] had received on May 29, 2013, contains the following statement:
“… referring to the present summons for [OPs to be held on] July 4, 2013, and the annex to the summons to OPs [the patent proprietor] files a new main request and eight auxiliary requests and simultaneously abandons (unter gleichzeitigem Verzicht) the requests filed so far.”
The request filed before the OD is encompassed by the expression “the requests filed so far”.
“Abandonment” (Verzicht) means the irrevocable renunciation (endgültige Aufgabe) of a right. Whoever uses the word “abandonment” has to accept the consequences. At any rate, this is true for a professional representative such as the representative of the patent proprietor.
A declaration of abandonment of a request has a dual – i.e. substantial and procedural – nature. It is immediately successful in both respects. From the point of view of procedural law it is equivalent to the withdrawal (Rücknahme) of a request. However, unlike a withdrawn request, which can in principle be re-introduced into the proceedings – if the competent division or Board admits it - a request that has been abandoned cannot be filed afresh. This is due to the substantial aspect of the abandonment: the declaration of abandonment results in an immediate loss of the abandoned object.
During the OPs the patent proprietor confirmed the declaration of abandonment and the fact that it was a procedural statement. However, it was of the opinion that the declaration of abandonment, which had been filed together with the requests referred to as “main request” and “auxiliary requests 1 to 8” in its letter of May 29, 2013, was not to be admitted into the proceedings because the requests had not been admitted either.
This opinion ignores the nature of a declaration of abandonment, which has an immediate effect. Therefore, the declaration of abandonment cannot be the object of an admission by the Board. This holds true, even if the [opponents] give their approval to a treatment of the abandoned request. The abandonment is not a “request” (Antrag) within the meaning of Article 12(4) RPBA and not a “case” (Vorbringen) within the meaning of Article 13(1) RPBA.
The present Boards considers these views to be in agreement with the case law of the Boards of appeal, which distinguishes between an amendment or withdrawal of a request on the one hand and an abandonment of a request on the other hand. See e.g. T 828/93  and T 922/08 [2.1]. This distinction clearly is based on the assumption that an abandonment has the consequence that a request cannot be treated in the proceedings any more.
Accordingly, the Board was hindered from admitting the request filed before the OD into the appeal proceedings, regardless of the fact that the opponent approved its admission.
So be careful which words you use in your written submissions.
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