I think of link text is a "mini-contract."
What the link promises should be obvious.
Don't use links that are just numbered cross-references - they don't communicate any meaning at all.
Graphical menus/link maps with no text are confusing. What are the chances a novice user or first time visitor can guess what function is provided? How many users will totally miss that the image is "clickable?"
Clicking should "fulfill the contract" (provide what was promised.)
There should be no "surprises" (such as links referencing non-existent documents, or pages under construction.) Links to long documents should include a terse summary and a size.
The RKT philosophy is to create good, descriptive document titles, that uniquely and accurately describe the topic. Then the document titles are used as the link text.
How the RKT Tools Help
The RKT tools automatically insert HREF anchor links when a topic title is placed in backquotes, and check and validate links while indexing.
Copyright 1998, Forrest J. Cavalier III Mib Software High Reuse Software Development