Hi Anitha

For a string list attribute, you can associate it with a Script Based Value Set to give you a set of values that show up when you click on Add.

Here are the steps:

1. Create Value Set

Sample script based Value sets to add:
-------------------------------------------------
dojo.provide("com.example.ValueSetProvider");

(function() {
    dojo.declare("com.example.ValueSetProvider", null, {

        getValueSet: function(attributeId, workItem, configuration) {
            
            var result= [];
            result.push("Yes");
            result.push("No");
        result.push("InProgress");
            return result;
            
        }
   });
})();


2. Create Attribute
   Type : String List
   Value Set: (Select the set created in step 1).

3. Add Attribute to Editor Presentation with Kind : String List.

You can also add a new values that are not part of the set returned by the script but that value will confine to that work item only.
A new work item will again show only the value set returned by the associated script.

For more information,
http://www.ibm.com/developerworks/rational/library/customize-rational-team-concert-non-traditional-uses/#_Customize_the_new

If you want one choice of the three, you want to create an enumeration. If you want to be able to select multiple values, you want an enumeration list. As far as I can tell, 4.x supports enumeration lists.

Read

https://jazz.net/library/article/1003

And the articles referenced at the end of the article to understand the process. You can also go through https://jazz.net/library/article/1093 to understand work item customization.

In an enumeration your literals would be, for example
Yes
No
In Progress