Of particular importance for examiners are online technical journals from scientific publishers (e.g. IEEE, Springer, Derwent). The reliability of these journals is the same as that of traditional paper journals, i.e. very high.

It should be noted that the internet publication of a particular issue of a journal may be earlier than the date of publication of the corresponding paper version. Furthermore, some journals pre-publish on the internet manuscripts which have been submitted to them, but which have not yet been published, and in some cases before they have even been approved for paper publication (for example, the "Geophysics" journal). If the journal then does not approve the manuscript for publication, this pre-publication of the manuscript may be the only disclosure of its content. Examiners must also remember that the pre-published manuscript may differ from the final, published version.

Where the given publication date of an online journal publication is too vague (e.g. only the month and year is known), and the most pessimistic possibility (the last day of the month) is too late, the examiner may request the exact publication date. Such a request may be made directly through a contact form that the publisher may offer on the internet, or via the EPO library.