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European Classification (ECLA)
The ECLA classification system is an extension of the International Patent Classification (IPC). It is however more precise, having twice as many entries (ECLA: 140 000; IPC: 70 000).
EPO examiners use it to classify patent documents and thus facilitate their prior-art searches. ECLA is revised continuously, and the documents are then reclassified accordingly.
ECLA usually follows the current IPC; up to IPC subgroup level, the ECLA and IPC classification symbols are in most cases identical. Optionally, the ECLA classification scheme may be further subdivided beyond IPC level by ECLA subgroups represented by a letter which may in turn be followed by a digit and a letter (e.g. B65D81/20B2A).
If you want to search globally below IPC subgroup level, you should use the * wildcard. For example, if you enter B65D81/20* in the ECLA field, you will get a lot of hits including ECLA groups such as B65D81/20B2A, B3, D, F1, etc.
Whereas if you only enter B65D81/20, you will get far fewer hits, confined to that particular subgroup.
To view the text of a specific ECLA class, go to Classification Search, where you can navigate to any classification. Simply type the relevant classification symbol in the field "Find description for a symbol" and then click on "Search".
To see whether or not the ECLA group is aligned with the IPC, tick the box next to "show notes" and read any warnings (see e.g. A61F).
When a document is given an ECLA classification, its family members (documents claiming exactly the same priorities) are automatically given the same classification. If an examiner notes that the contents of a specific document differs from those of the first document classified, a different ECLA class may be assigned.
You may occasionally come across the symbol ECLA IDT. This has an historical background. Initially, the EPO used an old documentation collection known as IDT, inherited from the Dutch office via the former IIB. This collection was classified only in the IDT system, and not in ECLA. Some years ago, for a subset of it, ECLA classification symbols were generated semi-automatically on the basis of data kindly supplied by the German office. The superscript "IDT" tag indicates ECLA symbols thus created. Because these symbols were not allocated intellectually by EPO examiners but generated by concordance several years ago, they are inevitably less accurate than proper ECLA ones.
It is estimated that 90% of the documents requiring an ECLA classification get one within eight months after publication.
For best search results, you are advised to combine queries in the ECLA/IPC fields with queries in the Abstract field.
The space for displaying symbols is limited in the extended view format of the result list. A number displayed in brackets next to the classification, for example (+3), indicates how many more symbols can be viewed by clicking on the patent title.
For more information on patent searching, see the following pages: