Change in number formats for CN-A documents
November 2004: Change in number formats for CN-A documents in Derwent World Patents Index
The data format of the CN-A application numbers changed during 2003 from:
YY1NNNNN
to
YYYY101NNNNN (new raw data format)
Under the current Derwent World Patents Index conversion rules for CN-A application numbers, this means that two separate numbers can be output in identical format. For example:
CN 1423505 A published on 11 June 2003 has the application number 03100020.7 and is output in DWPI as 2003CN100020
CN 1493872 A published on 5 May 2004 with application number 200310100020.8 is output in DWPI as 2003CN100020
To avoid incorrect patent families and delays to the data load, we have changed the format of the CNA application number for applications filed from 7th October 2003 to:
YYYY11NNNNN
All applications filed up and including 6th October 2003 will have the old format application number.
Therefore, in the example above:
CN 1493872 A published on 05/05/2004 with application number 200310100020.8 will be output in DWPI as 2003CN1100020
This change will be implemented for the front file immediately, and backfile records are also being corrected to remove existing duplicate numbers.