Using about.html to debug information centers

When developing an information center sometimes not all of the books show as expected or customizations do not have the desired effect. The about.html page can be used to get information about installed plug-ins and help system preferences. If the home page of the help system is

http://<hostname>:<port>/help/index.jsp

the about page has a url of

http://<hostname>:<port>/help/about.html

Without any parameters the about page shows a list of all plug-ins installed on the system. Parameters can be added to show other kinds of information as follows: