Category External Link is for Wiki pages which serve primarily to link to something of interest outside of Wiki Wiki Web.
In June 2001 Marko Schulz proposed to Delete This Category. While quite a lot pages are in this category he saw no benefit or use in this. Hereupon some uses were proposed:
find quickly all the external links, such that they can be checked for link rot (or even pre-emptively, such as the rumored dot-org revalidation)
valuable external links. Explore them to see what other users of this wiki found valuable and useful. First address for useful bookmarks.
those wishing to study the wiki, in itself a fascinating subject to some, would find it handy.
like some other Category Categorys which don't have a strict topic/content containment, it's useful for serendipitous exploration ... some quite curious pages can be discovered this way, and unlike Random Pages it has sufficient semblance of order that it sidesteps the accusation of aimless wandering.
Ward might extend this Wiki to but a little image beside all external links or links within the Category External Link. This would make the exit points of this wiki more visible. Nobody stepped up to claim that he actually uses this category in any of the ways proposed above. Still the decision was reached that this category should remain. A lot of work went into it and the benefits of deleting it are marginal.
Some discussion moved to Categories Discussion.
I find it interesting that there is a Category External Links page with discussion to keep or delete and nobody has edited or contributed to this page since 2001 and there is not one external link on the whole page. -- David Lippincott
This page provides a Reverse Index to pages with external links. It's not a place to put external links.
I expect there will be a lot more merit in this page moving forward.
Just during the 12 months that I have been learning about wikis, I have noticed an incredible growth in the number of wikis that are available.
I really appreciate that Wards Wiki, as the oldest wiki, has an extremely well developed sense of community; part of the reason for its success. That being said, other communities such as Wiki Pedia have emerged and are obviously succeeding in serving information needs of a different nature. I believe there is merit in linking to these from this site, while making it obvious where the link terminates so that one knows where one is likely to end up. Extending the use of a category such as this to allow one to infer who has recommended the link as a significant further benefit. (One of the reasons I buy Microsoft's Encarta is because I 'trust' their editors to effectively filter much of the web's content that I find irrelevant or biased.)
On that basis (and in the hope that many of the www's wikis will find their own sense of enduring purpose) I suspect there will be significant benefit in finding ways to Weave them together (perhaps creating a Ww Ww (WovenWWW) or even a Wiki Woven Www). -- Hans Wobbe
Declare And Link, Insert By Linking, and
wikifeatures.wiki.taoriver.net 
suggest putting URIs Once And Only Once on only a single page of the entire wiki.
(Software enforcement of this processes might reduce spam). If such a URI was mentioned on several pages, someone could refactor it to a single page, the kind of page that would be tagged Category External Link.
Are External Wiki Link and Category External Link mutually exclusive (i.e., does Category External Link refer to static pages that are not part of any wiki) ? Or is External Wiki Link a subset of Category External Link (i.e., does Category External Link refer to all non-c2.com pages) ?
See original on c2.com