[Zope] How to restrict the rendering of public methods?

Is it possible to restrict a method to be rendered only by another method? For example, what if we don't want "standard_html_header" to be rendered by itself? Currently, typing "(path)/standard_html_header", in example, renders the correspondant part of the page, because that method is already supossed to be permitted to view to all users, due the methods who would use it (like index_html) will inherit that permission. But, what if this turns out to be a security issue? Is it possible to turn all methods to be "system-callable-not-rendereable only", unless specified? Thanks in advance, Ausum