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Panorama needs access to all these files.  The Panorama documentation
describes the ways in which its entityrc and catalog files need to be
configured to access these DTD files (or at least it did in previous
versions of the accompanying manual).

Michael

Michael Fox
Head of Processing
Minnesota Historical Society
345 Kellogg Blvd West
St. Paul MN 55102-1906
phone: 651-296-1014
fax:  651-296-9961
[log in to unmask]
**NOTE NEW AREA CODE EFFECTIVE JULY 12, 1998**

> ----------
> From:         Bill Landis[SMTP:[log in to unmask]]
> Sent:         Thursday, May 13, 1999 10:39 PM
> To:   Multiple recipients of list EAD
> Subject:      Re: Necessary files
>
> In response to Charles Cofone's message earlier this week regarding the
> EAD DTD and its associated files, I'm appending below the chunk from the
> "EAD v1.0 Application Guidelines" (forthcoming from SAA this summer) that
> deals with the DTD. This won't address Charles' specific question about
> Panorama, but it may help in figuring out the role of the various files
> associated with the DTD.
>
> Bill [log in to unmask]
> Manuscripts Librarian                |                   The UCI Libraries
> Department of Special Collections    |            University of California
> 949 824.3113                         |                      P.O. Box 19557
> 949 824.2472 FAX                     |              Irvine, CA  92623-9557
>
> <begin excerpt>
>
> 4.3.  Technical Issues in Authoring
>
> This section provides discussions of the following technical issues as
> they relate to the authoring of EAD documents:
>
>  The structure of the EAD DTD and its associated files
>  EAD as both an SGML and an XML DTD
>  Parsing EAD instances to verify conformance with the DTD
>  Data interchange between MARC records and EAD finding aids
>  Effects of encoding features on output
>
> 4.3.1.  Structure of the EAD DTD
>
> The EAD Document Type Definition (DTD) is an essential component of the
> authoring process.  As a document, the DTD is constructed according to a
> strict syntax specified by the SGML standard.  For file management
> purposes, components of the DTD have been divided in a modular fashion
> into the ead.dtd file and four other associated files that function
> together as a unit.  Two of these (see below) are not required if the
> finding aid is encoded using EAD in XML mode. All five files are simple
> text documents in ASCII format that can be viewed and edited in text or
> word processing software.  The five files are:
>
>  ead.dtd
>  eadbase.ent
>  eadnotat.ent
>  eadchars.ent
>  eadsgml.dcl
>
> ead.dtd: This is the core EAD Document Type Definition file.  It is brief,
> containing a version history of the DTD plus entity references that invoke
> the other files in the EAD suite.  It also contains three conditional
> sections that enable or disable the following features:  XML
> compatibility, XLink functionality and the specialized features of EAD's
> array of tabular elements.  The use of these features is described in
> Sections 4.3.2.1 (XML compatibility), 4.3.5.4 (tabular layout), and 7.2.4
> (XLink functionality).
>
> eadbase.ent: This is the largest file of the group and contains the SGML
> rules for EAD.
>
> eadnotat.ent: This file contains references to the various types of
> notational (non-text) files that might be used within an EAD document.
> These include common image file formats such as GIF, JPEG, TIFF, and MPEG
> (see Section 6.5.2.4.2 for more information on notational files).
>
> eadchars.ent: This file contains references to the various character sets
> that might be used in an EAD document.  All character sets are referenced
> by their standard ISO identifiers.  This file is not required if the
> document is created in XML, which uses the Unicode character set (or some
> subset thereof) by default (see Section 6.5.2.1 for more information on
> character sets).
>
> eadsgml.dcl: This is the SGML declaration file, which specifies various
> features of the DTD that a processing application may need to know.  While
> many DTDs utilize a standard SGML reference declaration, EAD employs its
> own version.  Some software applications incorporate the text of the
> declaration at the beginning of each SGML instance.  All XML documents,
> however, employ a default declaration and so do not require the use of
> this file.
>
> 4.3.2.  SGML versus XML
>
> EAD is written so that it can be made to conform to the specifications of
> either SGML or XML.  The form of the DTD and its associated files that is
> available from the EAD home page at the Library of Congress is SGML
> compliant.  While XML may, in general, be thought of as a subset of SGML,
> there are five differences in XML that must be accommodated to make an EAD
> document XML-compliant.  You must be particularly aware of these
> differences when converting existing SGML versions of documents into XML.
>
> 4.3.2.1  Changes in the DTD Files
>
> If the DTD is to be used with XML applications such as validating
> processors, one change must first be made to the "ead.dtd" file.  There is
> a section towards the end of the file headed "SGML EADNOTAT AND EADCHARS
> INCLUSION/EXCLUSION."  At the end of this section, there is an entity
> reference that reads "<!ENTITY % sgml  'INCLUDE'  >".  To "switch off"
> SGML compatibility and "switch on" XML compatibility, change 'INCLUDE' to
> 'IGNORE'.
>
> When you make this change, observe that the explanatory note in this
> section of the DTD file points out that "for XML, the eadnotat.ent file
> should be invoked in the declaration subset of [the] individual instance."
> This means that the file "eadnotat.ent" must be explicitly declared as an
> entity in the prolog of each EAD instance that contains links to
> notational (non-textual) data such as graphics files (see Section 6.2.3
> for a general discussion of the document prolog).  For XML instances, the
> prolog of EAD-encoded finding aids should therefore read:
>
> <!DOCTYPE ead PUBLIC "-//Society of American Archivists//DTD ead.dtd
> (Encoded Archival Description (EAD) Version 1.0)//EN" "ead.dtd"
> [
> <!ENTITY % eadnotat PUBLIC "-//Society of American Archivists//DTD
> eadnotat.ent (Encoded Archival Description (EAD) Notation Declarations
> Version 1.0)//EN" "eadnotat.ent">
> %eadnotat;
> ]>
>
> While it is not necessary to declare the notation file "eadnotat.ent" if
> the finding aid does not contain a link to notational data such as
> graphics files, it is probably simplest to add it in all cases as a
> default.  Note that the Uniform Resource Identifiers (URIs), in this case
> simple file names that refer to the "ead.dtd" and the "eadnotat.ent"
> files, must point to the exact physical location of these two files on
> your system.  Their content may therefore vary from the above examples in
> accordance with your local storage practices for the DTD and its
> associated files.
>