2.2.1 Where claimed unitary subject-matter covers more than one technical field 

Exceptionally, where the subject-matter of an application covers two or more technical fields which are so different that a member trained to carry out searches in one field cannot reasonably be expected to search all of them, two or possibly even more members may share responsibility for drawing up the search report.

The skills needed to carry out a satisfactory search in a particular technical field include:

(a)the technical knowledge and training required to properly understand the claimed subject-matter 

(b)expertise in using the appropriate search tools. 

If the subject-matter of the application extends over different technical fields, it may be appropriate to enlarge the search division to include a second and possibly even more members who are specialised in those fields.

In all the above cases, the search report and search opinion (if applicable ‒ see B‑XI, 7) are usually issued by one member only.