The most strategic way to create headers/footers for Views is to implement the header or footers as a:
Global: View area (Global: View area)
that essentially merges the contents of another View into a View for its header. The subsidiary header View can be implemented by creating a purpose specific, very simple, custom content type, for example called, text snippets, whose only field is its standard body field, using the Full HTML text filter. The View to be used for the header can be implemented as a field display view that consists of the body field only, and which is content filtered on the ID of the desired text snippet node.
Although this method is more complicated on the surface, the other option, the:
Global: Text area (Global: Text area)
does not integrate with the ckeditor rich text editing, which makes editing the contents of that area with HTML markup rather a chore. Until the maintainers of Drupal core modify Views so that the header/footer feature integrates with the ckeditor editor, the method above provide optimal results.
