Derwent World Patents Index (DWPI) - EPI ... - Thomson Reuters

Part 3 Introduction
EPI Manual Codes 2011 947
Part 3
This third part of the EPI Manual Codes User Guide is intended to be used in conjunction with Parts 1 & 2 to
assist subscribers in making the best possible use of the intellectually-assigned indexing applied by
Thomson Reuters to electrical and electronic patents. The EPI codes may be thought of as a form of
technical shorthand, being an economical way of conveying often very specific information about a patent.
Manual codes are chiefly intended to serve as an online retrieval tool. By highlighting the novel aspects of
an invention and its applications, a highly focussed search can be conducted.
There are a number of ways in which the codes appropriate to a particular search may be determined; the
main ones being listed below :
1 By reference to the alphabetical subject index (page 3 in this manual)
2 By direct reference to the appropriate area of the code listing (Parts 1s 2 of this User Guide), if this
is known.
3 By reference to the IPC to manual code concordance (Appendix 3) for cases where the IPC for the
technology of interest is known.
4 By conducting a rough online search using keywords or IPCs for example, and employing
statistical analysis to determine the most-
(For full details of online searching techniques please refer to the relevant Derwent WPI Online User
Guide).
Whichever of the above methods is employed, it is essential that the user refers to the full entry for
suggested codes in Parts 1 & 2 of the EPI user manual, to verify that they represent the desired subject
matter. In particular, the scope notes for the suggested codes should be consulted, since they contain
information regarding certain topics that are excluded, or indicate other relevant codes.
In short, although the EPI Manual Codes User Guide has been published as three volumes, it is
essential that this third part is regarded as an aid to using Parts 1 & 2 and not used alone.
Subject Index
This index provides a detailed listing of technologies and indicates the corresponding manual codes. While
the intention has been to produce a comprehensive index, it is not possible to include entries for all
possible variations in particular technological fields without the result becoming very unwieldy.
Thus, in cases where a desired subject heading cannot be found as an index entry, alternatives such as
abbreviations, terms in full, or synonyms should be considered.