range
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An alternate approach, and the one recommended in this document, is
to assign a range of numbers specifically earmarked for testing and
experimentation purposes. Mutually consenting devices could use
these numbers for whatever purposes they desire, but under the
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... experimental uses.
Numbers in the experimentation range are similar to those called
"Private Use" in RFC 2434 ...
... likewise have the ability to chose and assign which number from the
experimental range will be used for a specific purpose (i.e., so the
end user can ensure that use of a particular number doesn't conflict
with other on-going uses). Shipping a product with a specific value
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... silently discard vs. signal an error), that
protocol needs to reserve values for testing purposes from all the
appropriate ranges. Only those implementations specifically enabled
or configured to make use of an extension or feature that is being
experimented with would process the data further.
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... specific protocol and factors specific to that protocol. For
example, in cases where the values of a field are subdivided into
ranges that are treated differently (e.g., "silently ignore" vs.
"return an error" if the value is not understood), one or more values
from each sub-range ...
... ranges that are treated differently (e.g., "silently ignore" vs.
"return an error" if the value is not understood), one or more values
from each sub-range may need to be reserved.
For protocols that return error codes ...