When defining a search macro, the required elements are the name and the definition of the macro. The name is a unique identifier for the macro that can be used to invoke it in other searches. The definition is the search string that the macro expands to when referenced. The arguments, validation expression, and validation error message are optional elements that can be used to customize the macro behavior and input validation2
1: Splunk Core Certified Power User Track, page 9. 2: Splunk Documentation, Define search macros in Settings.