We have a plugin that extends the JSP editor with our own tags on the
palette. It is used in our custom projects (which include the
org.eclipse.wst.common.project.facet.core.nature), but the projects do
NOT have the JSF nature applied to them. We don't do anything with JSF
whatsoever.
In the page editor, if any of our custom tags are dropped into the
Source Page, WST is automatically inserting a JSF taglib directive at
the top of the page:
<%@taglib uri="http://java.sun.com/jsf/core"; prefix="f"%>)
This obviously is annoying, but it also makes the page fail validation
and fail to compile/run.
Someone here mentioned that there was an Eclipse bug report about this,
but I could not find anything in Bugzilla.