From the start of WeRelate, use of Wikipedia content has been critical both to get initial reasonable content for many pages. In particular, "PLACE" pages. But exposure and use of wiki research/scholarship also makes it clear that - even if people were available to reproduce the work that was obtained from Wikipedia - doing so would be an enormous wasted effort. Far better to use the added effort and time to build up and upon what already exists.
Subsequent to the initial semi-automatic inclusion of over 70,000 wikipedia pages in order to flesh out the WeRelate PLACE page set, work began to merge large and rather chaotic GEDCOM uploads that arrived in the early years of WeRelate's existence. It was quickly realized that Wikipedia pages could be used to great advantage in that process. PERSON pages created only on the basis of GEDCOM content, were often very thin indeed. Recognizing when two such pages were duplicates was often not easy - but it was often much easier to recognize - in the context of a Wikipedia biography - that two existing GEDCOM-generated PERSON pages - in fact referred to the same person.
Over the last several years, a great deal of existing content has been successfully and correctly merged, in addition to adding large amounts of formerly absent content. There are now some 75,000 places backed by a companion Wikipedia page, and over 20,000 person pages likewise supported by a Wikipedia biographical page (see Wikipedia Biography Inclusion Project).
Besides place and person pages, it was always known that other sorts of Wikipedia pages could be helpful in WeRelate. Pages for wars, battles, military units, honors, houses of nobility, titles of nobility, and elected offices could be cited with an ordinary external Wikipedia link on an appropriate fact description line. While this is perfectly functional, it left something to be desired. Knowing that a certain individual had a particular association (and a reference to a descriptive page) was all very good, but good genealogists want to know ALL the people who were thus involved. There also might be added genealogy-specific information that we want to add related to ALL the people in such a group. Such information may not be useful, appropriate, or welcomed on a companion wikipedia page - so what to do?
Categories, of course, provide a great deal of what we seek. Moreover, a fair bit of work has already been done to associate individuals with appropriate categories. Notable examples include houses of nobility and military units of the American civil war. Up to now however, it has been customary to only set category membership using the syntax [[Category:(name)]] somewhere in the body of a person page. Almost any sort of category you may want to add a person to, is going to correspond to something that should be recorded as a fact in that person's life. So this would mean creating entries both in the fact list but also in the page body.
Thankfully, it turns out that there is no restriction on where category membership syntax can occur on a Person page. So, instead of adding categories when appropriate to the body of a Person page, it is proposed that category membership be established in the description fields of the facts to which the category is most obviously related.
Several templates have been developed, to simplify the creation of common category-facts, along with useful links that allow navigation to the associated category. These include:
Categories and Wikipedia
While the point of having a category is to collect multiple pages associated with a common item, it also provides a great opportunity for association with wikipedia scholarship other than associations with PERSON and PLACE pages. This sort of use of Wikipedia has been made for some time, but it hasn't been of a great deal of use - presumably because the process of creating associations was not obvious nor helpfully related to genealogical fact-oriented information collection.
The most well developed example at present, is probably the "NobleHouse" category. That page consists of a Wikipedia inclusion of the Wikipedia page for "Hereditary title". Below that, appear the members of the category, over 140 different family groups carrying inherited titles at some point in history. Each of the members in this case is also a category, and will often contain inclusion of a specific related Wikipedia page. For example, the House of Capet opens with an extract from the Wikipedia page for direct early members of that house. Later members belonged to one of several cadet branches of the family, which are reflected on the primary Capet page as sub-categories. For example, the sub-category House of Bourbon also contains Wikipedia inclusion, besides being a member of the Category for House of Capet.
The most extensive example of a category hierarchy appears to be the unit organization from the American Civil War found in American Civil War veterans, which is further broken down by State and unit with each state. Use of the hierarchy is spotty, again perhaps, because creation of a fact indicating that a person was a member of a particular unit is not consolidated with adding them to the corresponding category. It is hoped, that the templates above can help address that difficulty. An extensive example of use of the above templates can be found on the page for Gen Joshua Lawrence Chamberlain.