57Certainly, in order to justify refusing access to a document, it is not sufficient, in principle, for the document to fall within an activity or an interest referred to in Article 4(2) of Regulation No 1049/2001; the institution concerned must also explain how access to that document could specifically and actually undermine the interest protected by an exception laid down in that article. However, it is open to that institution to base its decisions in that regard on general presumptions which apply to certain categories of documents, as similar general considerations are likely to apply to requests for disclosure relating to documents of the same nature (Commission v Technische Glaswerke Ilmenau, paragraphs 53 and 54, and the case-law cited).