@<memoryaddress> in variable declaration

I found this variable declaration in code for a Freescale microprocessor:

extern volatile ADCSC1STR _ADCSC1 @0x00000010;

It is obvious what it does (store the variable _ADCSC1 to the fix memory address 0x00000010), but I'm not sure if this is a microcontroller/IDE-specific feature or something that is defined in the language standard of C. I'm not able to find ANY reference to something like this, but maybe I'm just searching at the wrong place.

Any hints are appreciated, thanks.

See HC(S)08 Compiler Manual, page 400.

It's a vendor specific extension called Global Variable Address Modifier.