Very obscure and technical question - Does anyone have any insight into paragraph 5.4.9.4. and 5.4.9.5. of the Vision Council's Data Communication Standards?

"5.4.9.4 In the particular case where BSIZ and CSIZ are absent or unknown and a single side tracing and two CIRC orCIRC3D values which differ are received, the CIRC or CIRC3D for the eye sent should reflect the shape. CSIZ isimplied to be the difference between the two circumferences and the shape for the eye not sent shall be modifiedaccording to the implied CSIZ.

5.4.9.5 When CIRC3D is present, either z-data, or a FCRV value, shall be included. If z-data is included, the value ofCIRC3D shall be calculated using the z-data; if only FCRV is included, the value of CIRC3D shall be calculated basedon the FCRV value."

It explains the requirements for a "CIRC3D" tag in an .oma shape file but does not go into detail as to the function of the tag. I understand the basic concept of a 3D vs. 2D shape, but it is not clear to me how data should flow from Tracer to Edger using that tag and the frame curve/Z data.

Any help at all would be greatly appreciated!