# Issue ## Description Currently, general base sections are located in the `eln` module and need to be moved to separate module. These sections include: - `Entity` - `System` - `Ensemble` - `Substance` - `Instrument` - `Activity` - `Process` - `Measurement` The plan is to create a new module `basesections.py` in `nomad.datamodel.metainfo`. ## Tasks - [x] Copy the above mentioned base sections - [ ] Find way to notify users about deprecated sections