what exactly does -v1 do?

[Tyler Knott]

Lars Ivar Igesund wrote:
> Language features added to DMD after release 1.000 will not work when using
> that switch. 
> 
Except they do work?  This compiles on DMD 1.007 with -v1 (as the only flag) without error:

void main() { mixin(`int foo;`); } //mixin declarations are definitely post-1.0