Avoid RFC 2317 style delegation.

[Jonathan de Boyne Pollard]

LV> if you don't own whole class C block you will have to follow RFC2317

He *can* follow RFC 2317.  He most certainly doesn't *have to*.  What he 
does is a private matter between him and the owners of the enclosing 
superdomain.  However, if he wants to continue to use the convenience 
features of his DNS (and possibly DHCP) softwares (This seems likely, 
given that he used one such feature in the very post that you are 
replying to.), he'll arrange with the owners of the enclosing 
superdomain to avoid RFC 2317-style delegation, because it breaks quite 
a few such features.

<URL:http://homepages.tesco.net./~J.deBoynePollard/FGA/avoid-rfc-2317-delegation.html>