{reg} This displays only to logged-in users {/reg}
* {pub} This displays only when the user is NOT logged-in {/pub}

When you hide text based on user groups, you'd use:

* {author} Authors only {/author}
* {editor} Editors only {/editor}
* {publisher} Publishers only {/publisher}
* {manager} Managers only {/manager}
* {admin} Administrators only {/admin}
* {super} Super Administrators only {/super}
* {special} Authors and above {/special}
* {groups:super users,administrators} Super Users or Administrators{/groups}

NOTE: Joomla does NOT fire plugin events when it renders content in PDF or RSS feeds, so therefore this plugin will NOT get triggered. Any text restricted by HIDER will be displayed, and any other content plugins you have will NOT get triggered. This is a Joomla issue, not an issue with the content plugins.