To help address the existing interoperability issues when using tabular material (“tables”) in SGML implementations, SGML Open's Technical Committee formed a Table Interchange subcommittee to research these issues.

Because the CALS table model has proliferated widely, it was chosen as the initial starting point. Although it has evolved to the point of a de facto standard, the specification leaves a large number of semantics open to interpretation which in turn has made interoperability difficult to achieve. As its first major task, the Committee therefore set out to identify and document ambiguities in the CALS table model specifications, identify and document related interoperability issues between SGML Open vendor products, and lay the groundwork for developing a proposed clarification of the standard that will minimize ambiguity and maximize interoperability.

This paper summarizes the results of this initial work, identifies the sources of current interoperability issues for the CALS model, and summarizes the most common set of practices currently followed by SGML Open vendors.