Extant MatInstances

I noticed in the console log that a dump of Extant MatInstances was ocurring when running in debug mode:
-------------------Extant MatInstances-------------------------
Mat: WarningMaterial
-------------------dump complete ------------------------------

I tracked this down to code in matInstance.cpp , but I cannot find any information on what this means. I suppose it could be comforting to know that it is only one material and that material is the generic "no material" mat.

extant: Still in existence; not destroyed, lost, or extinct.

Thanks