Specification
The ELN file format is based on Research Object Crate (RO-Crate) specification.
It can be summarized as a zipped RO-Crate.
The up-to-date specification is available on the GitHub respository:
Verify a .eln
Use this app to verify a .eln validity: https://check-eln.streamlit.app/
IANA media type
The .eln is an officially recognized media-type by IANA: vnd.eln+zip.