This category concerns the common Data Binding attributes found in
Internet Explorer 4.0+ - they allow a data source (commonly a field in
a database) to be tied to an element.
In HTML 4.x a Parameter Entity
called "%reserved" is also defined that contains these same attributes.
These attributes are not actually explained or defined in the standard other
than a cryptic "reserved for possible future use" notation in the DTD. These
attributes do not appear in any XHTML DTDs.
The IE data points in these support charts are taken directly from Microsoft's
own documentation on this subject.
Indicates the URL or ID of the data source object supplying the data that
is bound to this element. HTML 4 and Internet Explorer 4 diverge here on
intent of this attribute - HTML 4 indicates it should be a URL while IE4
says it should be a data source ID.