Navigation Tags (This library provides display tags for navigation use. <p>Display tags need data tags to provide them with content to display since they only contain the logic for formatting and generating HTML. The actual content is provided with data tags. <p>Every display tag has a mechanism to consume data tags. The most straight-forward way is via an attribute that takes an identifier (ID) that every Data Tag needs to declare. <p>Some of these tags have a scope argument. The valid values for the scope argument are "tag", "portlet request", "http request", "session", "persistent session", "application". These values are not case-sensitive, although it is considered a best practice to use all lower case.<p>The display tags in the Navigation tag library (plugnav) require PTURL DO data found in the Data Tag library (ptdata). <p>See the Data tag library (ptdata) for definitions of the different types of data.)