An executable function, as a whole, including all of its program logic, is always designated as a function. Subsets of a form's program logic can optionally be designated as subfunctions if there is a need to secure those subsets.

For example, suppose that an executable function such as a form contains three windows. The entire form is designated as a function that can be secured (included or excluded from a responsibility). Each of the form's three windows can be also be designated as non-executable functions, which means they can be individually secured. Thus, while different responsibilities may include this form, certain of the form's windows may not be accessible from each of those responsibilities, depending on how function security rules are applied.