Hiding the Guest Role
To hide the Guest role in a local team, a site or organization administrator can set the value of the Hide Guests Group preference in the Display category to Yes in the Preference Management utility on the Utilities page under Site 
or Organizations 
.
or Organizations .After the preference is set to Yes, the Guest role is then hidden from users in all existing and new application contexts. The preference value can be changed at any time, however the change affects all application contexts within your site or organization, rather than individual application contexts. Setting this preference does not require a restart of the server; saving your changes automatically refreshes the page and the preference setting is active.
 | If a user is in the Guest role of an application context when the above preference is set to Yes, then that user’s access control rules are not altered, and that user cannot be removed from the now hidden Guest role until and unless the property is set back to No and an administrator manually removes the user from that role. |
For more information on preferences and the Preference Management utility, see Preference Management.