You can muck around alternate data streams like a classic resource fork of a file on macOS by appending

   /..namedfork/rsrc

to the file name.

   ls ./groovyFontFile/..namedfork/rsrc

https://stackoverflow.com/a/42216808/8878480

I've tried it with ancient font suitcases -- the ones that pre-date dfont (data fork only) fonts.

It's somewhat ironic that all desktop file systems these days support myriad data streams on a file. I've implemented some on NTFS, played with extended attributes across tar archives between Linux and Mac and Windows. It's all there, but no longer used.