Under Art. 123(2), it is impermissible to add to a European application subject-matter which is not directly and unambiguously derivable from the disclosure of the invention as filed, also taking into account any features implicit to a person skilled in the art in what is expressly mentioned in the document. Literal support is, however, not required by the wording of Art. 123(2) (see T 667/08).
The term "implicit disclosure" means no more than the clear and unambiguous consequence of what is explicitly mentioned in the application as filed. Whilst common general knowledge must be taken into account in deciding what is clearly and unambiguously implied by the explicit disclosure of a document, the question of what may be rendered obvious by that disclosure in the light of common general knowledge is not relevant to the assessment of what the disclosure of that document necessarily implies (T 823/96).