LiquidFiles Documentation
This FAQ assumes you're running v2.6.9 or later

When a user is logged in, LiquidFiles will set a body class with the user id and group id. For instance, when a user, that is a member of the sysadmin group visits the compose page, the body tag will look like this:

<body class="page_message page_message_new group-sysadmins user-admin-company-com" id="page_message_new">

The update is the group-sysadmins, and user-admin-company-com. These are the unique ID fields for the group and user. If you want to see what the unique ID is for the group or user, please go to Admin → Group or Admin → User, and click Edit. The ID is the first value listed.

These classes can now be used to create specific design for a specific user or group. Consider the following JavaScript override:

$(function() {
  $('.group-external-users .external_users_info').removeClass('hide');

together with this footer:

<div class="external_users_info hide" style="text-align: center;">Usage of this system is restricted to sending files to XYZ corp. Everything is being logged</div>

Normally, the footer would be hidden since it has the 'hide' class, and the JavaScript that is triggered when the group-external-users is visible on the page will remove the 'hide' class. So in effect, the external_users_info div will be visible to the external-users group but not to everyone else.