Trellis quantization parameter: when is it ignored?

I see in the Media SDK 2013 R2 manual this statement:

    "Due to performance reason on some target usages trellis quantization is always turned off and this control is ignored by the SDK encoder."

That's a little bit ambiguous to me, does it mean:

    1) Due to performance reasons, on some target usages trellis quantization is always turned off...

    Or 2) Due to performance reasons on some target usages, trellis quantization is always turned off...

I assume 1) but it's worth checking.

Also, can it be specified exactly what "some target usages" are?

Thanks,

Ryan