[pmwiki-users] restricting use of html to a specific group

[writeon1]

I want to use the following in the config file to permit use of blocks of html. I want 
to limit it to a specific group which is password protected. How can I modify the
markup to do this? I'd swear I saw this somewhere, but can't find it.

Markup(
  'html',
  'fulltext',
  '/\\(:html:\\)(.*?)\\(:htmlend:\\)/esi',
  "'<:block>'.Keep(str_replace(array('&gt;', '&lt;', '&amp;'),
  array('>', '<', '&'), PSS('$1')))");

Help appreciated (as always)
Brendan