context
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This document describes the operation of these mechanisms in the
context of numbers allocated according to the ITU-T recommendation
E.164 ...
... field but can simply take the Preference value "on advisement" as
part of a client context specific selection method.
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... as a subtype for a different registered type but it is not sufficient
to simply reference another type's subtype. The function of each
subtype must be specified in the context of the type being
registered.
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