In the paper describing the binary table extension , type name 'BINTABLE' [10], the authors present three conventions: one for variable length arrays, one for multidimensional arrays and one for substring arrays. These conventions, discussed in appendixes to the proposal, are not part of the formal BINTABLE rules adopted by the IAUFWG but are expected to enjoy wide acceptance. The draft text for those appendixes, available on-line in the directory http://www.cv.nrao.edu/fits/documents/standards/ , is reproduced here nearly verbatim; the only changes are those required for stylistic consistency with the rest of this document.