Knowledgebase: Setup
Can I edit an existing registration form instance or should I create another form?
Posted by Z-Lori Crowell on 19 February 2008 05:39 PM
It is not recommended to edit existing registration form instances since this may change a registration form that is in use on another object (generally an activity or satellite site) within CME360. The best practice is to create a template with a specific name so that you can identify this registration form in the future and create the instance from that template.

Ref: Working with Registration Form Templates and Instances