On 27/04/2016 08:28, Adrian Farrel wrote:
...
Section 6
Include hint on best practice for top and bottom of ranges.
OLD
Reserved: Not assigned and not available for assignment. Reserved
values are held for special uses, such as to extend the
namespace when it becomes exhausted. Note that this is
distinctly different from "Unassigned".
NEW
Reserved: Not assigned and not available for assignment. Reserved
values are held for special uses, such as to extend the
namespace when it becomes exhausted. Note that this is
distinctly different from "Unassigned".
It is common practice for documents that define numeric registries
to mark the zero value as "Reserved" because this often aids
protocol
implementations.
I'm not sure about the "because" clause. It sounds a bit like an excuse for
sloppy coding. Defining it explicitly as a no-op would seem like better
practice in many cases.
Brian
It is also common practice to mark the maximum
value as "Reserved" so that it can be used as part of a strategy to
extend the registry if the range proves too small in the future.
END
Thanks,
Adrian