Uniquely French as a nominally distinct document type
As a document type, in terms of administrative phraseology, the “certificat d’addition”, as a nominally distinct type of document, may be unique to the administrative culture of France. Other nations have similarly filed patents, specifically making reference to earlier patents upon which they are building, but these additions have no different document type name, and are numbered in the ordinary manner as they fall chronologically in the flow of patents filed with the appropriate national patent office.
Within the French system(s) of patent registration and documentation, a “certificat d’addition”, almost invariably abbreviated as “cert d’addition”, or even “cert d’add”, is a patent registered in a manner specifically and formally treating it as an addition to some parent patent. Original documents show both the earlier number and a new number, which will be invariably and conspicuously lower than the number of the parent patent and conspicuously lower than the numbers given to filed near its point in time. In cases in which we discover a patent solely by way of such catalogues as the Bulletin Officiel de la propriété industrielle & commerciale or the French Catalogue des Brevets d'Invention we may only have access to the new number. When a French patent is included within Espacenet, it will be primarily searchable by way of the added number, though the principle number will be viewable on the original document itself.
In the cases of French patents, these “certs d’addition”, will be a key instance of our using the “Supplementary to patent” field. (There are other instances, in which a new registration isn't necessarily an addition to an earlier patent, per se, but still makes reference. References are also made to equivalent patents filed earlier in other nations. This usually refers to the internally significant priority date.)
The phrase “cert d’add” will occasionally be found within the patent's title, particularly within the antique catalogues.
Again, this distinction in terms of document type seems to be purely “nominal. Legally, and internationally, these documents are equal to patents, in that their filing dates are used as points of reference, both nationally and internationally. A later certificate of addition, or on occasion another patent altogether, may refer to one of these. A patent filed within some other nation may refer to one of these, usually by the filing date, treating it exactly as a patent. Technically, and semantically, within the French system, a "certificat d'addition" differs from a "brevet". This may be a matter of mere semantics, but it is to be noted when comparing analogous protocols internationally, or when noting the lack of said analogous protocols.
Semi-analogous procedures within other national systems
Belgium also uses the term "brevet", equaling “patent”, as in the case of France, but rather than distinguishing between the "brevet" and any equivalent to the "certificat d'addition", as such and as technically another type of document, the Belgian system has three types of "brevet", one being the "invention", another being the "importation", and another being the "perfectionnement". These "improvements" are invariably associated with preceding "inventions", but each "perfectionnement" will have its new number, a number falling logically relative to the numbers of the other patents filed in the surrounding days, weeks, and so forth, whereas an array of French brevets numbered as 3__,___ will be aligned with an array of additions numbered as 2_,___ or 3_,___. Thusly, these protocols are imperfectly analogous.
Great Britain, for instance, along with Hungary, and Austria, likewise have patents which are noted as additions to earlier patents, though also, like Belgium, they do not treat the later patent as a nominally different type of document. In the case of these two nations, the practice is fairly rare.
In the case of Great Britain, we have cases in which one specific and separate patent is specifically called an addition to another. We have also not entirely clarified the relation between the British "complete" and "provisional" specifications, particularly as these pertain to numbering and quantification. See Patent GB-1914-15494 for a sharp case of a Provisional Specification, of a certain number, being followed by two more provisional specifications, of different numbers, all embedded within the same document and all contributing to one complete specification which uses the initial number.
It may be that all nations we are studying have some means of treating later inventions which are considered as improvements to be associated with specific, and earlier, patents, filed within the same nation. At present, France seems to be unique in semantically treating the successor documents as a separate type of document.
Format on this site
We are working towards a standardized titling of French additions, using the title of the original patent followed by a period and then the number of the addition, viz.
It is hoped that this system will clarify the relationship of patent groups, while avoiding the confusion arising from the second series of numbers used for additions.
An addition should have its own filing year in the page title, not the parent patent's filing year, e.g.: