Mixed-signal CDL netlist export

Where did you see this? I'm not sure what this "Mixed-Signal Netlisting Mode" is that you're talking about.

There are essentially two types of netlisters: "analog" (the most common, including all the ADE netlisters, the auCdl (CDL) and auLvs (Diva) netlisters, which are CDF-based in terms of controlling the formatting), and "digital" (the Verilog netlister, cdl (CDL) and lvs (Diva) which are based on NLP-properties on the symbol and stopping view to control the formatting). The only real case where you have a choice of which to use is the CDL netlister - and for the vast majority of PDKs, you'd use the "Analog" netlister. 

Which netlister type is selected is controlled via the $CDS_Netlisting_Mode UNIX environment variable, which can be set to Analog, Digital and Compatibility. This controls things like how parameters are displayed, and how ~> on an instance returns a property - whether it looks just on the instance or also in the CDF for the default. Nearly always you want Analog as the choice (because of ADE and PDK support), and rarely (usually for legacy customers that have very old flows) you want Digital (which unfortunately is still the default despite it being pretty rare to want that - the perils of not really being able to change fundamental defaults like this despite most of the universe having converged on Analog/CDF-style netlisting in the mean time). I hardly ever see anyone pick Compatibility. 

Not sure if this is what you're talking about, or it's something else? Perhaps you can reference where in the documentation you've seen this; I might be barking up the wrong tree.

Regards,

Andrew.