Your administrator creates the source link fields (with trace enabled) for each of the source trace types being managed. For example, your administrator could create an Implementing Source source link field (with trace enabled) and a Verifies Source source link field (with trace enabled) and make them visible on the Requirement and Test Case item types respectively.

There are additional setup steps required if you want your source traces to be automatically updated to reflect ongoing source member changes. For more information, see Source Traces: Best Practices.