Hi John,
I wasn't referring to using the trims as a means of mixing. To put it into slightly more specific terms, -6dbfs = the new 0.0, i.e., keep the peaks completely out of the red
zone.
I give this as a suggestion for recording input levels for the primary reason that it works exceptionally well with prosumer A/D devices and a lot of plugins, which is what the vast majority of the folks in this forum use for their productions.