Some confusion here, let me try and assist;
If there is an outer marker for a FAF, then you may not continue the approach beyond this point if RVR is below minima.
If there is no outer marker (or equivalent), then you may not continue below 1000' AAL if the RVR is below minima.
It is a case of one or the other. For IRT purposes, you very often fly at airfields where no outer marker exists and so it is easy to see why it is not well known in the CPL training environment.
Cheers, MC