SACD Warning--"Do not use liquid cleaning..." ?

Two of my SACDs that have this warning are on the Telarc label (Al Di Meola's _Flesh on Flesh_ and Ensemble Galilie's _From the Isles to the Courts_). The disc surface definately looks different on these.

I thought I remembered the instruction sheet for Auric Illuminator saying not to use it on Sonopress SACDs. Unfortunately, I can't find it the sheet.

My _Dark Side of the Moon_ SACD does not come with the warning but has a similar looking surface, which made me wonder if it has the same fragility issues.

Hooper: I used to get scratches with MS as well. But I realized it was the polish pads, not the product itself, that was causing the scratches. So now I just spread it around with the moistened end of my index finger. No more scratches.

Okay, I found this on the Auric Illuminator website, which seems to answer my orignial question:

Auric Illuminator is not compatible with early made hybrid SACDs made by Sonopress. You can identify SONOPRESS SACDs by a marking around the inner spindle circumference.

As of May 2003 Sonopress states "now we are using other materials and it is no longer necessary to have a special frontcoating. These discs have no sticker (warning against topical treatments) and you can clean the laserentry side carefully with special liquids like a normal CD." Therefore it is safe to apply Auric Illuminator to new Sonopress SACDs.

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I'm not sure what the "special frontcoating" was, but apparently that was the problem.