You can assign a unique name to portal resource using Manage Custom Unique Names Portlet or using the Portal SPI. Once unique name is assigned to a resource you can use that name to locate the resource using either the Portal Scripting Interface or XMLAccess Script
You can assign unique name to either Pages, Portlet Applications, Portlets, URL Mapping Contexts, User Groups, Web Modules, WSRP Producers by following these steps.
1) go to Manage Custom Unique Names portlets.
2) Click on the type of resource that you want to work on Ex. Page
3) Seach the Page to which you want to assign unique name.
4) Once the page is found click on the Edit button and it will show you a form where you can assign unique name to the page.
Restrictions: There are couple of restrictions on value of custom unique name
1) A unique name must not exceed 256 characters in length
2) This name should be unique within the portal