See github issue #55
The ignored status is temporary in order to allow implementation details to be hidden. At the end of processing a file RDoc allows all classes and modules to add new documentation to previously created classes.
If a class was ignored (via stopdoc) then reopened later with additional documentation it should be shown. If a class was ignored and never reopened it should not be shown. The ignore flag allows this to occur.
# File lib/rdoc/code_object.rb, line 251 def ignore @ignored = true stop_doc end