And further in the description of <f:subview>
<f:subview>
Container action for all JSF core and component custom actions used on a nested page
included via <jsp:include> or any custom action that dynamically includes another page
from the same web application, such as JSTL's <c:import>.
Syntax
Body Content
JSP. May contain any combination of template text, other JSF custom actions, and custom
actions from other custom tag libraries.
Attributes
Constraints
? Must be nested inside a <f:view> custom action (although this custom action might be
in a page that is including the page containing the <f:subview> custom action.
? Must not contain an <f:view> custom action. <-- Here
? Must have an id attribute whose value is unique within the scope of the parent naming
container.
? May be placed in a parent page (with <jsp:include> or <c:import> nested inside),
or within the nested page.
<f:subview id="componentIdOrImmediateExpression"
[binding="componentReference"]
[rendered="
{true|false}
"]>
This is not a bug, as the spec states no included file can have a <f:view> tag. We are going to add some more debugging output code in an effort to help the user diagnose the tag parsing exception though.