CHDs_temp folder?

Sorry if I missed it somewhere, but what is in the CHDs_temp folder?  Besides the obvious.  Are these for upcoming mame releases?  I saw that Soul Calibur II and Soul Caliber III are in there but not is the CHDs folder.

Thanks

I am in progress to re-pack all CHDs again (Part size is now 100MB). All CHDs that have still the old settings (part size = 20MB) are in this folder.

The goal is to have them done .......and all CHDs are in "CHD" ;-)

Thanks for the quick explanation.