Creole should be extensible. In the case of links, this extensibility is best already specified in the specification, since the extensions are metadata on the link not separate. Examples:
* Semantic web markup in ontology wikis. What class of relation between two resources (both represented by wiki pages or external links) is this link?
* Formatting extensions, like the desire to control new window/same window for links pointing to external links or images, or provide pop-up-description (title attribute) for these.

I therefore propose to define the link as 

-- [[GregorHagedorn]] - 2007-02-27