tags matched by a glob)
* "`backlink(page)`" - matches only pages that a given page links to
* "`creation_month(month)`" - matches only files created on the given month
+ number
* "`creation_day(mday)`" - or day of the month
* "`creation_year(year)`" - or year
* "`created_after(page)`" - matches only files created after the given page
"a/b" will not match a page named "a/foo" or "a/b/foo". To match
relative to the directory of the page containing the pagespec, you can
use "./". For example, "./foo" on page "a/b" matches page "a/foo".
+
+To indicate the name of the page the PageSpec is used in, you can
+use a single dot. For example, `link(.)` matches all the pages
+linking to the page containing the PageSpec.