Will Benfold

> Does this PR also take care of what is discussed in [CF/cf-conventions issue #223](https://github.com/cf-convention/cf-conventions/issues/223), i.e. to explicitly state the coordinate axis ordering in the content of the `grid_mapping` attribute...

Either I had some arcane reason to do this that's unfathomable to you guys, me and everyone else _or_ I wrote a bug. I'm inclined to believe it's the latter,...

I meant "multiprocessing" in the sense of "having work done by multiple processes", with no intention of implying a specific library

If I understand this issue and the PP spec correctly, it isn't possible to save a PP file with a non-Proleptic Gregorian calendar. Possibly behaviours for Iris when asked to...

https://github.com/SciTools/cf-units/issues/203 currently needs parallel changes in Iris, which seem quite relevant here - notably that pp files don't handle cf's "standard" calendar

> 1. loading from pp and saving to some other format e.g. netCDF - this will change the calendar of the output and can be considered a bug fix which...

We make breaking changes sometimes, and with good reasons. This will be a useful place to start if in future it becomes more important to match the actual meaning of...

> * load&extract used to be lazy, now data is realised @jamesp where are you seeing this? When I run your code then ask if the cube is lazy it...

PP load with various environments, using the user-provided file that prompted @jamesp's concern: ``` tag time (s) mem (mb) pp load&extract user 44.44 15 pp load,extract user 16.90 56 (iris-3.2-dask-2021.6)...

> Oh that's fine then, it's only the worst of both worlds 😆 I don't know, I thought it would have to pull things in at at least the chunk...