The document below outlines data requirements for an XML-based descriptive data standard. The list is structured using tabbed levels (items tabbed across one level are replicable within the higher level). Items in bold are required within their level (but the higher-level structure to which they belong may not be required) Comments are in {}.

	Treatment

	Treatment Name          {Free-text title for the treatment}
	Description                {Free-text description of the treatment}
	Treatment build/revision number            {A real numeric e.g. 4.1 used for version control}
	Treatment build/revision date            {Date string (standardised format?)}
	Contributors List                 {List of contributors to the treatment, including the principal builder}
		ID {Unique (in the context of this treatment) number for the contributor}
		Name {contributor’s name}
		Contact details {contributor’s address, email etc}
		Private notes {internal notes on contributor, not for parsing}
	Attribution {ID of principal treatment builder - this is the default attribution unless a lower-level 						item is specifically attributed}1
List of sources
	ID {Number for the source}
	Description {e.g. reference, description of specimen set etc}
Principal Source {ID of the principal (default) source for the data}1
	Treatment attachments {General information topics applicable to the treatment as a whole}
		Attachment name
		Attachment type {e.g. xml,html,txt,rtf,jpeg,gif}
		Attachment path/URL
		Public attachment notes
		Private attachment notes
	Private treatment notes {internal freeform notes for treatment}

	Character list source {path to an external lexicon that defines the character list for the treatment}
	Character set names list {list of set names for characters}
		Name {name string for a character set}
	Collation rules {Set of rules for collating characters - e.g. how to merge scores, calculate values, 							deal with conflicts in source data etc}2
		Name {A reference name for the rule}
		Rule definition {don’t know how these will be structured yet}

	Character List {required unless an external lexicon resource has been specified above}
		Character Name3
		Character ID
		Set membership {list of sets to which the character belongs; a character must be able to belong to 								more than one set}
		Attribution1 {reference to a contributor’s ID from the Contributors list}
		Source1 (reference to a source’s ID from the Sources list) 
		Collated Character source {path name for another treatment that contains lower-level data for this 										character}
			Collation rule name {Name of a collation rule as defined in the Collation Rules list}
		Character type {ordered multistate, unordered multistate etc}
		Character dependencies (up) 4
		Applies To list (or global/restricted type definition, then leave it to program to extract) 5
		Character attachments
			attachment name
			attachment type
			attachment path/URL
			Public notes
			Private notes
		Private notes {internal notes for character}

		Character State List

			Character state name | Character state ID
			Character dependencies (down)
			Character state attachments
				attachment name
				attachment type
				attachment path/URL
				Public notes
				Private notes
			Private notes

	Taxon list source {path to an external resource that defines the taxon list for the treatment}
	Taxon set names {defines a list of allowable names for taxon sets}
		name

Taxon List

		Name | Taxon ID
		Taxon set membership {list of sets to which the taxon belongs; a taxon must be able to belong to 										more than one set?}

		Taxon attribution1
		Taxon attachments
			attachment name
			attachment type
			attachment path/URL
			Public notes
			Private notes {not parsed}
		Private notes {not parsed}

	Item Data {This will hold the “score matrix”}
		Taxon Name|ID/Character Name|ID6
			Character Name|ID/Taxon Name|ID6
				State Name|ID
					Score {normally present, rare, present by misinterpretation etc}
					Public Notes
					Private Notes

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1 Attribution and sources for an item datum overides that for a character or taxon, which override that for the treatment as a whole. Attribution for characters and taxa are equivalent and additive.

2 Treatments are nestable. That is, one treatment may contain data on specimens, a higher-level treatment on taxa. The higher-level treatment gathers information for some characters from lower-level treatments, using the collation rules defined here.

3 Character names may be hierarchically nested. Character properties (e.g. sets, dependencies, attachments) are only specified for the lowest level characters.

e.g.
Leaves
	margins
		teeth
			orientation  }only these have
			shape          } properties

4 Dependencies may be defined either up or down (but not both?). An up dependency lists the character  states that make this character inapplicable; a down dependency lists characters that become inapplicable when this state is chosen.

5 The idea here is to specify a subset of taxa for which this character is scored, or to specify that the character is non-global, then leave it to the parsing program to determine the taxon list. This feature would be used by future identification programs that employ the Progressive Revelation model.

6 The item data may be stored as the equivalent of either a taxon-state matrix or a state-taxon matrix, depending upon whether taxa are nested within characters or characters are nested within taxa. There will need to be a way of specifying which of these is operative.