In my experience of reading on the web, most of the time that authors use links, they can be said to fall into one of the following general categories:
Expansions: More like this. Click for more of the same.
Responses: Counterarguments, ripostes, turnabouts.
Description: Zooming in for a detailed view of the subject.
Citation: A pointer to the original. (The vast majority of links.)
Of course, others can imagine very different systems of link types, which is one of the reasons that Tim Berners-Lee was right to mention not constraining link types, in his original proposal for the web. Here are Ted Nelsons's (from Literary Machines):
Metalinks: Title, Author, Version
Ordinary Links: Correction, Comment, Counterpart, Translation, Heading, Footnote.
Hypertext Links: Vanilla Jump, Typed (Modal) Jump, Suggested-Threading, Expansion.
Literary Links: Citation, Alternative-Version, Comment, Certification, (E)mail.
Randy Trigg, the man who probably studied link types in more depth than anyone else alive (his whole dissertation was all about link types), has an enormous library of them, which he classifies into two kinds:
NORMAL:
Citation: Source, Pioneer, Credit, Leads, Eponym.
Background.
Future Work.
Refutation.
Support.
Methodology.
Data.
Generalize.
Specialize.
Abstraction.
Example.
Formalization.
Application.
Argument: Deduction, Induction, Analogy, Intuition, Solution.
Summarization.
Detail.
Alternate View.
Rewrite.
Explanation.
Simplification.
Complication.
Update.
Correction.
Continuation.
And, COMMENTARY:
Comment: Critical, Supportive.
Related Work: Misrepresents, Vacuum, Ignores, Is Superseded By, Is Refuted By, Is Supported By, Redundant
Problem Solving: Trivial, Unimportant, Impossible, Ill-Posed, Solved, Ambitious.
Thesis: Trivial, Unimportant, Irrelevant, Red Herring, Contradict, Dubious, Counterexample, Inelegant, Simplistic, Arbitrary, Unmotivated.
Argumentation: Invalid, Insufficient, Immaterial, Misleading, Alternative, Strawman.
Data: Inadequate, Dubious, Ignores, Irrelevant, Inapplicable, Misinterpreted.
Style: Boring, Unimaginative, Incoherent, Rambling, Awkward.
