Extended shelves can have zero or more documents, uniquely defined by document ID. Each document must contain one or more instances, uniquely defined by type. Taken together, document instances can be described by these fields:

ID
Uniquely identifies the document within the extended shelf.
Type
Refers to the type of file the document instance is formatted in. Examples are PDF File or Softcopy Reader Book. This cannot be changed.
Name
Name of the extended shelf. This is required and must be 1-8 characters in length.
Title
Title of the document instance. This is required and has no specific format.
Update Timestamp
Date and time document instance was last modified. This is required. The format must be MM/dd/yy HH:mm:ss, where MM is the month of the year (1-12), dd is the day of the month (1-31), yy is the two digit year, HH is the hour of the day (0-23), mm is the minute (0-59) and ss is the seconds.
Update Comment
This is a place for putting comments about the last update. It is optional.
Subject, Keywords and Author
These are optional fields which further describe the document instance. There is no specific format for these fields.
Expiration Timestamp
This is the date and time the document is expired. The format is the same as the update timestamp. This field is optional.
URI
This the absolute URI location of the document instance. The use of this field is primarily for z/OS based platforms. This field is both optional and discouraged.

IBM® and Softcopy Reader® are registered trademarks of the
International Business Machines Corporation.