Each document on a web site excepting the homepage of that site must contain a link to the site's homepage. Any other sections of a web document devoted to the navigation of the web site of which it is a part must be consistently presented and positioned in unison with the other documents on that site.
Authors must try their best to facilitate orientation in website. Any navigation needs user's effort to be understood. If we make him orient more than necessary, he will leave soon. Navigation must therefore be comprehensible and similar on all pages.
Details: When navigation is made of more than one block of text, it must appear after the main information and must be referenced in the prologue.
User doesn't take care of navigation or other documents until he finds information he came for. Navigation must therefore be placed after the main document statement. Only if it is brief, one text-block sized (i.e. one paragraph), it may appear in the prologue. Otherwise there is only a reference to the navigation located below.
Especially large documents or presentations made available on a web site should be divided into sections, with each section linked to the beginning or prologue of the presentation.
Web documents should not be too long. But when it is necessary to put information into only one document, it must be divided into sections, with each section referenced from the prologue. That is to facilitate the orientation for reader (brief summary, index, etc.)
Details: All links into the document must be made so that the link target differs from the surrounding text.
When the user is moved to another part of the document, he must be able to find where he had been moved. In the link target there should be visible text - corresponding to that of link, preferably as a heading or other hilited form. The user must take long time to find the link target in surrounding content.