Also, e-commerce Internet applications could base their data elements on the rich XML data elements, facilitating the interapplication exchange of information among legacy applications and various types of Internet e-commerce applications.

An EDI and XML Example The "Purchase Order" at left illustrates a typical purchase order, while the "X12 Line Item Record" shown below outlines a single record from the purchase order. The record is the one used for the line-item in a purchase order. An X12 Purchase Order document has about 100 records, many of which can repeat. The first three characters--PO1--identify the type of record--in this case, it means a purchase order line-item record. Each new field starts with a data element separator, the "*" character in our example. The record varies in length and unused fields on the end of the record need not be there.

An XML representation for this record could look like this:

<po1>

<ass.Id>1</ass.id>

<Q.Ordered>54</Q.Ordered>

<Unit.M>EA</Unit.M>

<Unit.P>0.99</Unit.P>

<Price.C>CA</Price.C>

<Prod.ID.C>VN</Prod.ID.C>

<Prod.ID>456</Prod.ID>

</po1>

Notice, that while the XML version is more verbose than the X12 standard, it's not as position-dependent. Because each value is tagged, we know which data element each value represents. And since the value is tagged, it won't get lost. For the average Web server application programmer, this translates into less screen-specific programming and less dependence on CGIs.

How would XML affect catalog integration issues? Let's assume the following scenario: All office supply vendors selling No. 2 lead pencils agree to use the data elements as defined in a neutral data dictionary.