If you find references in the forum for /etc/66/boot.conf it is from the time that boot-66serv was just a bundle of services that could be configured through that file. Ever since last summer when boot@ became a module this operation had to be transferred to each module separately, so you could ultimately have different configured boot modules in different boot trees, and select which one to boot from the boot loader.
66-tree -n boot1
66-tree -n boot2
66-enable -t boot1 boot@ fileserver
66-enable -t boot2 boot@ desktop
then on the boot loader you add a TREE modifier at the end
linux ......... ro splash quiet ... TREE=boot1
linux ......... ro splash quiet ... TREE=boot2