+
+The rest of the members in an SPV file's Zip archive fall into two
+categories: structure and details. ``Structure'' member names begin
+with @file{outputViewer@var{nnnnnnnnnn}}, where each @var{n} is a
+decimal digit, and end with @file{.xml}, and often include the string
+@file{_heading} in between. Each of these members represents some
+kind of output item (a table, a heading, a block of text, etc.) or a
+group of them. The member whose output goes at the beginning of the
+document is numbered 0, the next member in the output is numbered 1,
+and so on.
+
+Structure members contain XML. This XML is sometimes self-contained,
+but it often references other members in the Zip archive named as
+follows:
+
+@table @asis
+@item @file{@var{prefix}_table.xml} and @file{@var{prefix}_tableData.bin}
+@itemx @file{@var{prefix}_lightTableData.bin}
+The structure of a table plus its data. Older SPV files pair a
+@file{@var{prefix}_table.xml} file that describes the table's
+structure with a binary @file{@var{prefix}_tableData.bin} file that
+gives its data. Newer SPV files (the majority of those in the corpus)
+instead include a single @file{@var{prefix}_lightTableData.bin} file
+that incorporates both into a single binary format.
+
+@item @file{@var{prefix}_warning.xml} and @file{@var{prefix}_warningData.bin}
+@itemx @file{@var{prefix}_lightWarningData.bin}
+Same format used for tables, with a different name.
+
+@item @file{@var{prefix}_notes.xml} and @file{@var{prefix}_notesData.bin}
+@itemx @file{@var{prefix}_lightNotesData.bin}
+Same format used for tables, with a different name.
+
+@item @file{@var{prefix}_chartData.bin} and @file{@var{prefix}_chart.xml}
+The structure of a chart plus its data. Charts do not have a
+``light'' format.
+
+@item @var{prefix}_model.xml
+@itemx @var{prefix}_pmml.xml
+@itemx @var{prefix}_stats.xml
+Not yet investigated. The corpus contains only one example of each.
+@end table
+
+The @file{@var{prefix}} in the names of the detail members is
+typically an 11-digit decimal number that increases for each item,
+tending to skip values. Older SPV files use different naming
+conventions. Structure member refer to detail members by name, and so
+their exact names do not appear to matter as long as they are unique.
+
+@node SPV Structure Member Format
+@subsection Structure Member Format
+
+Structure members XML files claim conformance with a collection of XML
+Schemas. These schemas are distributed, under a nonfree license, with
+SPSS binaries. Fortunately, the schemas are not necessary to
+understand the structure members. To a degree, the schemas can even
+be deceptive because they document elements and attributes that are
+not in the corpus and lack documentation of elements and attributes
+that are commonly found in the corpus.
+
+Structure members use a different XML namespace for each schema, but
+these namespaces are not entirely consistent: in some SPV files, for
+example, the @code{viewer-tree} schema is associated with namespace
+@indicateurl{http://xml.spss.com/spss/viewer-tree} and in other with
+@indicateurl{http://xml.spss.com/spss/viewer/viewer-tree} (note the
+additional @file{viewer/} directory. In any case, the schema URIs are
+not resolvable to obtain the schemas themselves.
+
+One may ignore all of the above in interpreting a structure member.
+The actual XML has a simple and straightforward form that does not
+require a reader to take schemas or namespaces into account. The