BOOTP and DHCP option 66 and 67 and PXE boot

If you read most PXE documentations you will see that it specifies option 66 for the TFTP server and option 67 for the boot image, however from my experiments with freeradius DHCP where all it does is provide raw DHCP decoding and encoding I discovered that most of the docs were written after testing with Microsoft DHCP which seems to conveniently translate 66 into the old bootp sname and 67 into old bootp fname.  So do not be surprised if you attempt to set 66 and 67 and that NIC card still does not boot.