Dear community, Back in March, I started a thread with the same subject on the Discussion list [1]. As recommended in the guidelines [2], I'm dropping you a line to let you know that I have started working on a netcdf frontend. I'm pushing the work in progress on a feature branch of my fork [3]. I'm about to load the input file with `netCDF4.Dataset()` in `data_structures.py` and I'll use the length and time units as parsed from the metadata. There is no mass unit though. Is there any way to mark it as 'not applicable'? Setting the mass unit to `None` currently leads to an error. I thought that the default `_particle_reader = False` in `io.py` would let you not consider particles and masses... Happy to continue the conversation on Slack! Thank you, Marianne [1] http://lists.spacepope.org/pipermail/yt-users-spacepope.org/2017-March/threa... [2] http://yt-project.org/doc/developing/creating_frontend.html#data-meaning-str... [3] https://github.com/mkcor/yt/tree/netcdf-autoloader/yt/frontends/netcdf