ADF Faces 11g does not contain tags such as af:head and af:body. Instead there is af:document, an abstraction from the documents served to potentially different clients.
A JSF page can be rendered as HTML – with a HEAD and BODY tag – but also to other clients and renderformats that do not have the HEAD and BODY concept. Hence the abstraction.
When your ADF Faces page does render as HTML to a web browser, the af:document will render both HEAD and BODY. If you want to specify the title attribute for the HEAD, you have to set the title attribute on af:document.
To set the values of meta-tags, you use code like this:
-- Note: that the f:verbatim is one way of dealing with the fact that <meta> is not a recognized nor allowed child of a facet or any other JSF component.