Glossary
Private rule
A private YARA rule is evaluated and can be referenced by other rules, but is never reported as a match on its own.
Declaring private rule Is_Small_PE { … } creates a building block: other rules can use Is_Small_PE in their conditions, but scanners do not list it among matches. Private rules help factor common checks (file type, size, shared markers) without cluttering results.
A rule must be declared before it is referenced. See YARA syntax.