An invention is considered to be new if it does not form part of the state of the art. For a definition of "state of the art", see G‑IV, 1. It is to be noted that in considering novelty (as distinct from inventive step; see G‑VII, 8), it is not permissible to combine separate items of prior art together. It is also not permissible to combine separate items belonging to different embodiments described in one and the same document, unless such combination has specifically been suggested (see T 305/87). For the specific case of selection inventions see G‑VI, 8.
Furthermore, any matter explicitly disclaimed (with the exception of disclaimers which exclude unworkable embodiments) and prior art acknowledged in a document, in so far as explicitly described therein, are to be regarded as incorporated in the document.
It is further permissible to use a dictionary or similar document of reference in order to interpret a special term used in a document.
An unclear term cannot be used to distinguish the invention from the prior art (see F‑IV, 4.6).