Wiki Visitor
A WikiVisitor is a WikiRole:
While in priciple every WikiUser can create or edit content, at any particular moment a WikiUser may not be doing so. And in some Wikis the WikiAdmin has configured things so that people need to create an account and be logged in to have write access.
The role with the least rights is for the one who merely visits or (where an account is needed for write access) for the WikiUser who has simply not logged in: a WikiVisitor is the role of someone who browses the Wiki content (usually without leaving a trace, or maybe leaving anonymous comments) but cannot create or edit content (or does not). Depending on system configuration by the WikiAdmin, a visitor may, or may not, be allowed to add comments to pages.
See WikiRoles for other roles related to Wikis.
