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Note to the METS list from Carl Fleischhauer and the audio-visual project
team at the Library of Congress, January 27, 2002.

We have been hashing over the re-design of the relational database from
which we propose to generate METS documents. In the course of this, we
found ourselves in need of help re: the primary schema and the "area"
element (which appears back to back with "sequence").  I won't try to say
this in XML-speak (I am XML illiterate) but will do my best to express the
question in lay language.

The _seq_ element is defined as "should be used to link a div to a set of
content files when those files should be played sequentially to display
content to a user.  Individual area subelements within the seq element
provide the links to the files or portions thereof."  This seems to be
about a group of files, understood to come one after the other.

The _area_ element is defined as providing "more sophisticated linking
between a div element and content files representing that div, be they
text, image, audio, or video files.  An area element can link a div to a
point within a file, to a one-dimension segment of a file (e.g., text
screen, image line, audio/video clip), or a two-dimensional section of a
file (e.g, subsection of an image, or a subsection of the  video display
of a video file."  This seems to be about "inside one file" and NOT about
a group of separate files.

We worry that this leaves "orphaned" a scanning phenomenon we encountered
in American Memory: "the billboard job."  For very large posters, for
example, we sometimes made several rows of images, representing tiles of
the oversized original.  In a perfect display system, these would come up
in a grid:
image.a1   image.a2   image.a3
image.b1   image.b2   image.b3
image.c1   image.c2   image.c3

Question: can we use the "area" elements to do this, or is there another
trick we didn't notice?  If not, perhaps this is a METS version-two
desideratum.

Thanks for the advice!  Carl