" IPP client and server implementations must be aware of the diverse
uppercase/lowercase nature of URLs. RFC xxxx defines URL schemes and Ho=
st names
as case insensitive but reminds us that the rest of the URL may well
demonstrate case sensitivity. When creating URL's, where the choice is
completely arbitrary, it is probably best to select lower case however,=
this
cannot be guaranteed and implementations MUST NOT rely on any specific =
case
type in the URL beyond the URL scheme and host name".
Harry Lewis - IBM Printing Systems
=