Problems with HTML links

Problems when using the HTML model for general XML:

Link syntax and semantics is not defined separately from rest of HTML:

• In HTML, links are recognized by element names (A, IMG, ..)
  - we want a generic XML solution.
• The "semantics" of a link is completely defined in the higher-level specification
  - we want control of general semantic features, e.g. of link actuation.

• An anchor must be placed at every link destination (problem with read-only documents)
  - we want to express relative locations (XPointer!).
• The link definition must be at the same location as the link source
  - we want out-of-line links ("link databases").
• Only individual nodes can be linked to
  - we want links to whole tree fragments.
• A link always has one source and one destination
  - we want links with multiple sources and destinations.
• Links are anonymous
  - we want human-readable labels.