The publication number is the number assigned to a patent application on publication. Publication numbers are generally made up of a country code (two letters) and a serial number (variable, 1-12 digits) (e.g. DE202004009768).
The publication numbers of published US applications, however, consist of 11 digits (e.g. US20040046892). Normally only the number of the first publication level is searchable.
The format of PCT (WO) publication numbers has changed over the years:
You can use any of these formats to enter PCT (WO) publication numbers in the Smart search mask, which uses fuzzy logic.
For certain countries, if you know the kind code, we recommend adding it to the end of the number in order to retrieve the document you want (e.g. ES1005422U). These countries are: Austria (AT), Chile (CL), China (CN), Germany (DE), Denmark (DK), Spain (ES), Finland (FI), Japan (JP), Korea (KR), The Netherlands (NL), Norway (NO), Poland (PL), Romania (RO), Sweden (SE), Turkey (TR), Taiwan (TW), and Serbia and Montenegro (YU).
In the publication number field, you may enter a maximum of ten numbers which will automatically be separated by the default operator OR.
When typing in a publication number, do not leave any spaces between the country code and the number.
To retrieve all the documents having a particular country code in combination with other search criteria (for example the date), all you have to do is enter the country code in the publication number field in combination with, in this example, the date in the publication date field.
For more information on Espacenet, see the following pages: