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The latest version of this topic can be found at C28302.

warning C28302: For C++ reference-parameter <parameter_name>, an extra _Deref_ operator was found on <annotation>.

This warning is reported when an extra level of _Deref_ is used on a parameter.

SAL2 does not require the use of an extra level of _Deref_ when dealing with reference parameters. This particular annotation is unambiguous and is interpreted correctly, but should be corrected.

Frequently this can be corrected by simply removing the older __deref annotation and using SAL2 syntax. Sometimes may be necessary to use _At_ to reference the specific object to be annotated.