'username' => the supplied username
'password' => the supplied password
'authenticated' => set this to non-zero to authenticate the user.
+ 'user_record' => successful authentication must also return a valid user record from the database
+
'logged_in' - called after a user has successfully logged in.
$b contains the $a->user array
$b is the item array of the information to be stored in the database
{Please note: body contents are bbcode - not HTML)
+'post_local_end' - called when a local status post or comment has been stored on the local system
+ $b is the item array of the information which has just been stored in the database
+ {Please note: body contents are bbcode - not HTML)
+
+
'post_remote' - called when receiving a post from another source. This may also be used
to post local activity or system generated messages.
$b is the item array of information to be stored in the database and the item
'contacts' => contact array of entries
'output' => the (string) generated HTML of the contact block
+'bbcode' - called during conversion of bbcode to html
+ $b is (string) converted text
+
+'html2bbcode' - called during conversion of html to bbcode (e.g. remote message posting)
+ $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