9.2.4 Intermediate documents 

Documents published between the priority date claimed in the searched application ‒ or the earliest priority date if there is more than one (see B‑VI, 5.2 and B‑XI, 4) ‒ and its filing date are labelled with the letter "P". The letter "P" is also used for a document published on the very day of the earliest priority date claimed. The document category "P" is always accompanied by one of the letters explained in B‑X, 9.2.1 and B-X, 9.2.2 to indicate its level of relevance. So e.g. "P, X", "P, Y" or "P, A".