+Ikiwiki currently only has one type of dependency between pages
+(plus wikilinks special cased in on the side). This has resulted in various
+problems, and it's seemed for a long time to me that ikiwiki needs to get
+smarter about what types of dependencies are supported.
+
+### unnecessary work
+
+The current single dependency type causes the depending page to be rebuilt
+whenever a matching dependency is added, removed, or *modified*. But a
+great many things don't care about the modification case, and often cause
+unnecessary page rebuilds:
+
+* meta only cares if the pages are added or removed. Content change does
+ not matter (unless show=title is used).
+* brokenlinks, orphans, pagecount, ditto
+* inline in archive mode cares about page title, author changing, but
+ not content. (Ditto for meta with show=title.)
+* Causes extra work when solving the [[bugs/transitive_dependencies]]
+ problem.
+
+### two types of dependencies needed for [[tracking_bugs_with_dependencies]]