Dear @JonathanGregory and @hrajagers, Here is a synthesis current proposal. How does it sound?
**(A)** The governance is written up along the lines of @hrajagers ideas: #153 (comment) **(B)** Comprehensive conformance rules are written up for UGRID. These should be maintained alongside UGRID in its repository, and referenced from (not copied into) the CF conformance document. **(C)** Document the standardised UGRID attributes in the CF conventions, thereby making them visible to all users. Mention in the governance rules that they need maintaining. Only the UGRID attributes which can appear on data variables (`mesh`, `location` and `location_index_sets` should be added to CF Appendix A. All other attributes UGRID attributes (such as those on mesh variables) should go into a new CF appendix specifically about the UGRID mesh topology variable, consisting of the table with an introductory sentence or two. This would be like the treatment of the attributes of the grid mapping variable, which are in a table in Appendix F, not in Appendix A. Note that the geometry variable attributes appear in Appendix A, but there are only five of them, whereas there are 18 attributes of the mesh topology variable. **(D)** Deprecate the `cf_role` attribute for connectivity variables (but retaining it on the mesh topology variable). If and only if @hrajagers and UGRID colleagues are in agreement, also deprecate the `cf_role` attribute mesh variables, deferring to the presence of the `topology_dimension` attribute for identification. This latter suggestion will make the mesh variable "more CF-like", but that is not worth at this time if the expense is a lot of broken existing software. **(E)** Add some text to CF 5.8 (Domain Variables) (now accepted for CF-1.9) to explain the UGRID mesh topology variable and how it relates to a domain variable. It may the case that the occasional note relating to UGRID would be useful in other sections. I don't propose to review for these, but they could always be added as when it was felt to be useful. **(F)** Add a short subsection of CF section 1 to introduce UGRID and its purpose, to make clear its special synergy with CF, to remark on the appearance of attributes in CF appendices, and to say that it has its own conformance document which complements the CF conformance document. Thanks, David -- You are receiving this because you are subscribed to this thread. Reply to this email directly or view it on GitHub: https://github.com/cf-convention/cf-conventions/issues/153#issuecomment-736382330 This list forwards relevant notifications from Github. It is distinct from [email protected], although if you do nothing, a subscription to the UCAR list will result in a subscription to this list. To unsubscribe from this list only, send a message to [email protected].
