Help: Clarify what MSVC compilers ignore <LANG>_STANDARD_REQUIRED
Fixes #20953
diff --git a/Help/prop_tgt/CUDA_STANDARD_REQUIRED.rst b/Help/prop_tgt/CUDA_STANDARD_REQUIRED.rst
index b923800..c9301b5 100644
--- a/Help/prop_tgt/CUDA_STANDARD_REQUIRED.rst
+++ b/Help/prop_tgt/CUDA_STANDARD_REQUIRED.rst
@@ -10,7 +10,7 @@
property is ``OFF`` or unset, the :prop_tgt:`CUDA_STANDARD` target property is
treated as optional and may "decay" to a previous standard if the requested is
not available. For compilers that have no notion of a standard level, such as
-MSVC, this has no effect.
+MSVC 1800 (Visual Studio 2013) and lower, this has no effect.
See the :manual:`cmake-compile-features(7)` manual for information on
compile features and a list of supported compilers.
diff --git a/Help/prop_tgt/CXX_STANDARD_REQUIRED.rst b/Help/prop_tgt/CXX_STANDARD_REQUIRED.rst
index 2ea2215..8b17490 100644
--- a/Help/prop_tgt/CXX_STANDARD_REQUIRED.rst
+++ b/Help/prop_tgt/CXX_STANDARD_REQUIRED.rst
@@ -10,7 +10,7 @@
property is ``OFF`` or unset, the :prop_tgt:`CXX_STANDARD` target property is
treated as optional and may "decay" to a previous standard if the requested is
not available. For compilers that have no notion of a standard level, such as
-MSVC, this has no effect.
+MSVC 1800 (Visual Studio 2013) and lower, this has no effect.
See the :manual:`cmake-compile-features(7)` manual for information on
compile features and a list of supported compilers.
diff --git a/Help/prop_tgt/C_STANDARD_REQUIRED.rst b/Help/prop_tgt/C_STANDARD_REQUIRED.rst
index c1b58a0..55bff04 100644
--- a/Help/prop_tgt/C_STANDARD_REQUIRED.rst
+++ b/Help/prop_tgt/C_STANDARD_REQUIRED.rst
@@ -10,7 +10,7 @@
property is ``OFF`` or unset, the :prop_tgt:`C_STANDARD` target property is
treated as optional and may "decay" to a previous standard if the requested is
not available. For compilers that have no notion of a standard level, such as
-MSVC, this has no effect.
+MSVC 1800 (Visual Studio 2013) and lower, this has no effect.
See the :manual:`cmake-compile-features(7)` manual for information on
compile features and a list of supported compilers.
