Annotations

Annotations are notes which are attached to specific words or sections of text.  Highlighting is a similar form of markup, because it is also attached to specific words and phrases.

Wiki support several forms of annotations by default: links, bolding and highlighting via fonts, semantic markups such as section headers and lists.  However, marginal text is not a common markup, and all of the above annotations require full write access to change the content.

Why Annotations?

If readers do not have access to change the main text, it can be a more direct method of making contextual comments than a list of comments attached to the page as a whole.

Even if editor can change the main text, sidebar annotations are a useful and popular feature of many dead-tree books.

Example implementations:

• http://www.annocpan.org/

Many annotation projects aim to be able to markup any web page and share the annotations.

• Web annotation on Wikipedia
• WebAnnotation on c2.com
  

Issues

Attachment: words, phrases, paragraphs/sections

Alter wiki text for markup, or not?

Overlapping annotations

Display: sidebar, popup, mouseover, etc

Suppress display of annotations, by type, date, etc.

Expiring old annotations.