[CF-metadata] axis attribute

[Jonathan Gregory]

Dear Richard

----- Forwarded message from Richard Gorman <r.gorman at niwa.co.nz> -----
> When I started writing code to handle NetCDF data, the files I was 
> dealing with used the axis = X and Y attribute for rotated pole 
> coordinates. So I took that interpretation to be standard and, like you, 
> coded to use that attribute as one way to identify the spatial 
> coordinate variables and dimensions.

What was the importance of identifying them as X and Y? Is it to decide which
one is the horizontal axis of the plot, for instance?

Cheers

Jonathan