> ... the presence of a **`dimensions`** attribute on a scalar variable will > identify the variable as a domain variable.
There is some confusion here ... Are we saying that a domain variable _must_ be a scalar? We don't insist on that for grid mapping and geometry variables (although it is [recommended for grid mapping variables](https://github.com/cf-convention/cf-conventions/blob/master/conformance.adoc)). If we say that for a domain variable, we should say the same for grid mapping and geometry variables - which I think would be a defect change (on the grounds that these variables were never intended to contain meaningful data arrays). Either way, this brings me back to @JonathanGregory's suggestion of disallowing `dimensions` as a data variable attribute, which I now think is OK (for CF versions starting at the one in which the domain variable goes in). So that first sentence could become ``` The dimensions of the domain must be stored with the **`dimensions`** attribute, and the presence of a **`dimensions`** attribute identifies the variable as a domain variable. Therefore the *`dimensions`** attribute must not be present on any variables that are to be interpreted as data variables. ``` The phrase *variables that are to be interpreted as data variables* means that variables that are *referenced* by data variables (such as auxiliary coordinate variables) may indeed have a **`dimensions`** attribute, but in that case such a variable cannot also be used as independent data variable (see, for example, the section "Interpreting CF-netCDF files" in https://doi.org/10.5194/gmd-10-4619-2017). -- 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/301#issuecomment-698851329 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].
