ar request, identified by the <tt>requestId</tt>
component.<p>

Management records have a <tt>requestId</tt> value of zero,
also called the <i>null request ID</i>.  Application
records have a nonzero <tt>requestId</tt>.<p>

The second distinction is between <i>discrete</i> and <i>stream</i>
records.  A discrete record contains a meaningful unit of data all by
itself.  A stream record is part of a <i>stream</i>, i.e. a series of
zero or more non-empty records (<tt>length != 0</tt>) of the stream
type, follow