Vector outputs various “portlets” consisting of a <ul> lists; it even recognizes some of those portlets are empty, and adds a CSS class named “emptyPortlet” to them. However, empty <ul></ul> is not a valid XHTML markup (at least one <li> element is required inside <ul>).
If a portlet is empty, no <ul> should be output at all.
Version: unspecified
Severity: trivial
URL: http://validator.w3.org/check?uri=http%3A%2F%2Fen.wikipedia.org%2Fwiki%2FMain_Page