From Joomla! Documentation

The "J1.5" namespace is an archived namespace. This page contains information for a Joomla! version which is no longer supported. It exists only as a historical reference, it will not be improved and its content may be incomplete and/or contain broken links.

Cross Reference: for more detail about levels of permission on a Joomla! site see, Controlling user access to a Joomla! Site
  • Open the User Manager
This lists users.
  • Create a New User
Click on the New icon

The User:[new] management page allows you to enter the details. To the left you enter the name and user name, as well as selecting the Group for the user. To the right there are options for other choices, including different editors. So you can make different choices for different users. If nothing is chosen under Parameters, then the Global choices will be used.

The options available for adding a new User and selection of the right Group