Renaming Aliases 
Aliases allow you to express a rule in an easily understandable manner. An alias is the representation of a Java method or object in an user-understandable language.
In the Project Explorer view, expand the rules composer DC node, the Rules Modeling node and double click the Aliases node.
The Project Aliases Editor appears as shown below:

In the Project Alias Editor, choose the XSD Aliases/Class Aliases tab and in the Alias Name table, choose the element/method to be renamed.
Note
Press F2 and enter the alias name and press Enter
A valid alias name
Must not be null
Must not match any name present in the rules composer
Supports case sensitivity. For example 'Customer Name' and 'customer name' are two different alias names
Ruleset Aliases
You can also rename the Ruleset alias names.
You need to add classes in the rules composer DC.
More information: Adding a Class
You need to create a definition whose type is a java type in the rules composer DC.
More information: Creating a Definition.
Example
Let us consider a java type — java.util.ArrayList.
In the Project Explorer view, expand the rules composer DC node, the Rules Modeling node and double click the Aliases node.
In the Project Alias Editor, choose the Class Aliases tab.
Under Alias Name column, choose the ArrayList [java.util.ArrayList].
In the Project Explorer view, expand the rules composer DC node, the Rules Modeling node and double click the ruleset node and choose the Definitions tab.
In the definitions editor, under the Variable Definitions section, choose the Add icon and in the drop down that appears, select ArrayList [java.util].
In the Definition Name dialog box that appears, enter myList and choose OK.
Choose null and in the drop down menu that appears, expand the ArrayList [java.util] and choose new ArrayList as shown below.

To open the Ruleset Alias Editor, in the Project Explorer view, expand the rules composer DC node, the Rules Modeling node and double click the Ruleset tab.
In the Ruleset Editor, choose the Aliases tab and in the Alias Name table, choose the method to be renamed.