While that is quite the tongue twister, it makes an important point. Merriam-Webster defines context as "the interrelated conditions in which something exists or occurs". In my opinion, "interrelated conditions" is the part of the definition which is the most significant.
Wikis by design are a collection of pages without a specific hierarchical structure. However, Socialtext makes it very easy to build relationships between pages, even across multiple workspaces.
First, tagging allows you to add keywords to a page. They can be about the content itself, the project which the page is a part of, about the author, the status, or anything else you feel helps define the page. When clicking on a tag, all pages with that tag are displayed, providing an easy way to discover and organize similar content.
Second, Socialtext wikis provides the concept of "page includes". What that means is, you can assemble a page, by including multiple other pages inside it. Think of it like assembling an object from multiple building blocks. However, in this case the building blocks can be used in multiple places at the same time. When they are updated, all the places they are included in are also updated.
Third, pages in Socialtext provide you with links to all the other pages which reference the one you are looking at. If a clickable URL is considered an outgoing link, than think of these as incoming links. This allows you to have a greater understanding of a page's place in the larger scheme of all your content.
These features whether individually or combined, help Socialtext users understand the context of their content. When you understand the "conditions in which something exists or occurs", you can tailor what you write, with the comfort of knowing who will be reading it, and where.
Socialtext is very good in this regard.