3.13 Technological background 

In certain circumstances it may be desirable to extend the subject-matter of the search to include the "technological background" of the invention. This would include:

– the preamble to the first claim, i.e. the part preceding the expression "characterised by" or "characterised in that"; 

– the state of the art which in the introduction of the description of the application is said to be known, but not identified by specific citations; 

– the general technological background of the invention (often called "general state of the art").