Perfectionnement
This is one of many francophone ways of saying “improvement”. Within the patent documentation system of Belgium, it is also the formalized term for a patent of addition, roughly equivalent to France's cert d'addition, in which a new filing not only makes reference to an earlier invention, but is specifically and formally an addition to it. As usual, these patents are numbered. Unlike the case of French certificates of addition, these Belgian “perfectionnements” will have numbers which do not stand out conspicuously within the timeline. Though reference is made from one patent to another, the new patent itself has only one number, whereas the French certificat d'addition will not only mention, but titularly feature both the “original” number and the added number specific to the addition.
Within the Catalogue de Brevets d'Invention - Belgian, or within the Recueil des Brevets d'Invention, a simple “(perf.)”, as opposed to “(inv.)”, will be the sole indication that we are dealing specifically with an addition to some earlier patent. The Belgians distinguished between “improvements” and per se “inventions”. Earlier Belgian data also mentions the “importation” type of patent, that is, a patent for an invention which had been patented previously outside of Belgium. All of these are “inventions”.
Minor and rare confusion is to be avoided in that the word “perfectionnement” is still used more generally, on occasion, within our French and Belgian material, within patent texts and titles.
A “perfectionnement” is an action of making perfect, or of perfecting.[1]