sal-annotations.md

title	description	ms.date	ms.topic	helpviewer_keywords	ms.assetid
SAL Annotations	A brief description of the Microsoft source-code annotation language (SAL).	11/04/2016	conceptual	__z annotation ref annotation _opt annotation __checkreturn annotatioin __deref_opt annotation deref_opt annotation __deref annotation __in annotation annotations [C++] z annotation _inout annotation __ref annotation full annotation _in annotation _ref annotation __out annotation _ecount annotation SAL annotations __opt annotation inout annotation in annotation _CA_SHOULD_CHECK_RETURN __bcount annotation _full annotation _bcount annotation deref annotation part annotation _out annotation __nz annotation __part annotation opt annotation __full annotation _nz annotation _z annotation out annotation __ecount annotation __inout annotation SAL annotations, _CA_SHOULD_CHECK_RETURN _deref_opt annotation _deref annotation nz annotation _part annotation ecount annotation bcount annotation	81893638-010c-41a0-9cb3-666fe360f3e0

SAL annotations

If you examine the library header files, you may notice some unusual annotations, for example, _In_z and _Out_z_cap_(_Size). These annotations are examples of the Microsoft source-code annotation language (SAL). SAL provides a set of annotations to describe how a function uses its parameters and return type. For example, it indicates the assumptions it makes about them and the guarantees it makes on finishing. The header file <sal.h> defines the annotations.

For more information about using SAL annotations in Visual Studio, see Using SAL annotations to reduce C/C++ code defects.

See also

C runtime (CRT) and C++ Standard Library (STL) .lib files