What's the purpose of the -v1 switch?

[Trass3r]

I mean it can only be used with dmd 1.x compilers anyway.

else if (strcmp(p + 1, "v1") == 0)
{
#if DMDV1
        global.params.Dversion = 1;
#else
        error("use DMD 1.0 series compilers for -v1 switch");
        break;
#endif
}