```
@Documented
@Retention(CLASS)
@Target(PARAMETER)
public @interface FormatString
```
Annotation for method parameter declarations which denotes that actual parameters will be used as a format string in printf-style formatting.
This is an optional annotation used along with the FormatMethod annotation to denote which parameter in a format method is the format string. All parameters after the format string are assumed to be printf-style arguments for the format string. For example, the following snippet declares that logMessage will be used as a format string with args passed as arguments to the format string:
```
 public class Foo {
   @FormatMethod void doBarAndLogFailure(@FormatString String logMessage,
       Object... args) {...}
 }
```
See FormatMethod for more information.

Annotation Type FormatString