Unclear scope of session_id, tissie_id, cell_id, etc

Came up in a discussion with @bendichter that there is no mandate on either those (and actually subject_id as well) should be defined globally, per dataset, per subject, and/or per session, etc. Global level would have been the best but infeasible. Also it would likely to require longer IDs, thus making organized filenames inconveniently long.

Some of them seems to have inherent upper scope limit, at least in the prevalent majority of the cases, eg tissue sample with the same id can't come from different subjects. Cell - from different tissues.
Situation is not as clear at subject or session level. Is subject id defined for the dataset, is centralized to lab or some other entity - archive (eg guid in nda), country (SSN), registry (orcid), or global (yet to establish interplanetary registry).
Session - are two subjects with the same session id (eg based on date) participate in joint behavioral experiment, or session id is just to disambiguate within subject? Is cell id, to disambiguate within session or subject or tissue?

I think, per each of the IDs we (or nwb? bccn?) should establish clear default scope, but we might want allow to explicitly state or modify it in dandiset.yaml .

.... more later, need to run