Why BIOS maps in range 0x000F0000-0x000FFFF ?



Why BIOS is mapped to 0x000F0000-0x000FFFF address range.
I know it has to be within 1 MB but my doubt is why it is above
particular range(0x000F0000-0x000FFFF ) within 1 MB.
Is it simply a standard or it has some significance ?

Thanks
Das

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