| Storage Class Specifier | At Namespace Scope | at Class Scope | at Block Scope |
|---|---|---|---|
| none | internal linkage if const, external otherwise; static storage | no linkage; storage allocated as part of enclosing object | same as auto |
| auto | - | - | no linkage automatic storage |
| extern | external linkage unless previously declared with internal linkage; static storage | - | external linkage unless previously declared with internal linkage in an enclosing scope; static storage |
| register | - | - | same as auto |
| static | internal linkage; static storage | external linkage; static storage | no linkage; static storage |
| Note: An empty entry indicates an invalid combination of scope and storage class specifiers. | |||