The most important facts/claims about a patent are its inventors, its applicants, its title, the country where it was filed, the date it was filed, the date it was granted, and its official number. It is also useful to know how the government classified its technology (as aircraft or locks or light bulbs), its official links to other patents, its transcription on Wikisource, and URLs or other references for more official information about it. Although this list is not complicated, representing the information on Wikidata can be tricky, because (a) we don't have the simplest properties available, and (b) there are many quirky variations. The practices below are pretty good.
Most important properties of a patent item:
- Use issued by (P2378) and identify the office with which the patent was filed -- generally a bureau that is an instance of patent office (Q1148446)).
- Use applies to jurisdiction (P1001) and then the Q-number of the national government/country.
- Use country (P17) and then the Q-number of the national government/country. It does not need to be a country that still exists. This technique is perhaps more flexible, and it will be necessary to use this option if it is not known what bureau received the patent application.
- A patent application (Q3022019) which has not (yet) been granted may also be a Wikidata object; such an item might use the other fields but would not have a grant date. Let's add an example here if we find one.
- Inventors/applicants There is always at least one applicant, and usually at least one inventor. Often these are the same, but in some cases these lists can actually be disjoint -- e.g. if an inventor sold the patent rights to a firm, or if if the inventor died and another person is following the application through.
- Inventors: There can be zero or a list of these. Inventors are individuals not organizations, in any patent known so far. Use author name string (P2093): string to store unspecified author name for publications; use if Wikidata item for author (P50) does not exist or is not known for each inventor. For inventors which are known to Wikidata, that is, are represented by Q-items, also use discoverer or inventor (P61): the entity who discovered, first described, invented, or developed this discovery or invention. List them all to the extent possible. There may be zero inventors if there is only an Applicant, which might be a company which does not identify the individuals who created the invention. This is not common but there are examples.
- I missed this one: inventor (Q205375), but I don't know what property to use to launch it on a patent item.
- Possible future development: We could put the inventors in order, marking a "first" one, by imitating the format for authors of a "scientific article" which have an order ("ordinality") recorded in Wikidata. See for example this scientific article, which puts the authors in an explicit order. It is not clear yet whether there is legal or historical significance to which patentee is listed first, but WIPO does not always list inventors beyond the first one in historic patents, and there are social scientific papers using the first patentee especially, e.g. to identify the location of the invention's occurrence, so there cases -- maybe only these minor ones, in which order is used.
- Applicant(s) are different from the inventor(s), if (a) a company or organization filed the application, or (b) the inventor died and someone else is filing, or (c) the inventor assigned local management/ownership to someone in the relevant country. For humans maybe also use applicant (Q54875338). That attribute requires the applicant to be a human, not an organization. For now, use author name string (P2093): string to store unspecified author name for publications; use if Wikidata item for author (P50) does not exist or is not known for each applicant, but we will someday want some difference in property to distinguish these. Will want to show some example patents illustrating hard cases in the property request.
- Title: Use title (P1476), and fill it with a string in the language of the patent application; optionally, add translations to that property.
- Patent number: If google patents has the patent, use: (patent number (P1246)). This will not work for all patents because google patents does not have them all AND because the format is restrictive, requiring format like US891393. Usually this works but in some historical cases there are letters in the 'number' (1BB##### in 19th century France, though possibly the 1BB can be left out), and there may be cases in which there is no proper number, so this item is optional but will be there in >99% of cases. Note that patent number in this format does not include year and so is not unique e.g. in Great Britain numbers were reused year after year. One approach would be to define a more flexible "historic patent number" property, and just make it a string. We might try inventory number (P217).
- Page title on Wikidata: Titles are not at all unique, and patent numbers were not always unique per country. It is okay for the title to be nonstandard, but for mass-upload cases we could use this standard: Patent plus country plus year plus number, e.g. "Patent US 1906 821393". In my research on historic patents that would achieve uniqueness. There are reasons to allow letters in the patent "number" -- French 1BB prefix and the suffix A or E used by WIPO to distinguish main patents from "additions" or "extensions" to earlier patents. In existing sources the year is sometimes the filing year and sometimes the grant year.
Less important or rarer properties:
- publication date: historically this was sometimes later than grant date -- we want either publication date (publication date (P577)) or (less likely) date of publication (Q1361758). This date does not seem to have great historic significance -- it's the date of an administrative act of the patent office, not the historically more significant acts of (a) an inventor filing a claim and establishing priority, or (b) the patent office granting the claim, and thus giving the inventor a monopoly.
- Wikisource id can point to a transcription of the original patent document(s). Perfect transcriptions are not generally available; Wikimedia can add value here. The Wikisource id does not seem to have a property number; it's located in a special section of the Wikidata item near the bottom of the editing screen.
- Wikisource index page (P1957) is a way to link to a Wikisource "index page", as is done in this example: The Education of Henry Adams (Q7731604): book by Henry Adams. Most patents aren't on Wikisource and don't need to be.
- end time (P582): could give the date on which a patent grant was scheduled to end, at the time it was granted. Sometimes 1-5 years, sometimes 15, sometimes 17. This is somewhat complicated since some patents required annual renewal, and not normally worth enough to put into Wikidata, but we could document some general duration rules here.
- Parent patent or child patent: Having filed for one patent, an applicant may file another characterizing it as an "addition" or "extension" or "supplementary patent" to the first, and then the claims in the new patent receive legal priority that go along with the filing date of the first patent. In French the second one is said to be a certificate d'addition, or cert d'addition. Or the applicant may file for the same patent covering another jurisdiction, e.g. French inventor may file for a patent in Germany. The mechanisms have changed over time; a hundre years ago this kind of action was explicit, whereas now it is more completely covered automatically by treaties and checkboxes. Either way, these relations (a) supplementary patents, and (b) foreign identical patents, create relations from a patent to its "parent" or "child" patents. These relations could ideally be recorded in the Wikidata item. The WIPO term for a cluster of patents is a "family" so one way to do this is to make the "INPADOC family ID" at WIPO an external id in an external database. It's more simple and informative to record more explicitly which one patent is the first ancestral "parent" of the others. One way to record a child patent is to make "patent of addition" a property, and quality it with information about the patent that is its parent.
- Assignee: The applicants may give rights over to another company, organization, or set of persons. This can be important. We do not have a recommended way to record that yet.