This specifies that the current CMake code is written for the given range of CMake versions, <min>[...<max>]. It sets the "policy version" to:

• the range's <max> version, if specified, or to

• the <min> version, or to

• the value of the CMAKE_POLICY_VERSION_MINIMUM variable if it is higher than the other two versions.

The policy version effectively requests behavior preferred as of a given CMake version and tells newer CMake versions to warn about their new policies. All policies known to the running version of CMake and introduced in that version or earlier will be set to use NEW behavior. All policies introduced in later versions will be unset (unless the CMAKE_POLICY_DEFAULT_CMP<NNNN> variable sets a default). This effectively requests behavior preferred as of a given CMake version and tells newer CMake versions to warn about their new policies.