bcc32c.exe #defines _MSC_VER if -A (Enable ANSI conformance) option given

Hi, I've got this test program:

#ifdef _MSC_VER
#error _MSC_VER is defined
#endif

int main()
{
    return 0;
}

Using bcc32c.exe (version 7.30), if I compile this without the -A option then it compiles fine. If, however, I specify the -A option to enable ANSI conformance, then it apparently predefines the _MSC_VER macro and hits the #error directive, failing to compile.

Is this behavior intentional? I could not find anything mentioned about it in the accompanying documentation (.chm). Also, this behavior happens only with the Clang-enhanced compiler (bcc32c.exe), and not with the classic Borland compiler (bcc32.exe). I don't have the other compilers in my setup to test with.