oem-logo & oem-banner ???



If you type in the shell "nvram -p" you will notice two variables : oem-logo and oem-banner.

Do you know what are they for ?
Do you know how to use and set them ? (when I say "set" I don't mean how to change the value, I know it : nvram varName=value, but what to write as value and what does it refer to. I suppose it's something like a picture, so if this is exact, what format to use : pict, raw, ... ?)

Thank you very much,
sorry if it's not all right english,
There are many remnants of Next in the system, beyond programmatic services. Maybe the oem (original equipment manufacturer) variables were from the Next port to the Intel suite of compatibles.