$b is (string) converted text
+'page_header' - called after building the page navigation section
+ $b is (string) HTML of nav region
+
+
+'personal_xrd' - called prior to output of personal XRD file.
+ $b is an array
+ 'user' => the user record for the person
+ 'xml' => the complete XML to be output
+
+
*** = subject to change