Matthew Evans

I strongly support adding idea of linking out to persistence into the API; I would go one step further and suggest that we added some kind of persistent URL field...

> As the references' properties/fields are currently BibTeX one-to-one (see [description of the `references` endpoint and entry type](https://github.com/Materials-Consortia/OPTIMADE/blob/develop/optimade.rst#references-entries)), this will introduce a shift away from that. This isn't true for...

One easy alternative would be to bulk up our definitions to encompass BibJSON, itself based on bibtex http://okfnlabs.org/bibjson/ (I think this was discussed a while ago). BibJSON in fact includes...

We've just run into this again over at https://github.com/Materials-Consortia/optimade-python-tools/pull/560. The question is whether the specification requires values of SHOULD fields depending on the values of other SHOULD fields, e.g. if...

Although we don't currently mandate 1. in the specification, it's somewhat implicit in [6.2.7 Filtering on releationships](https://github.com/Materials-Consortia/OPTIMADE/blob/develop/optimade.rst#filtering-on-relationships) where the only examples given are for filtering on relationships of ``, since...

I think I added this in #336... wasn't aware of this previous effort. Using pycheckspelling to skip code blocks could be useful though, I had to add several edgecases to...

Paging @BobHanson

I think it might be worth reopening this; there are a few databases that require API keys to access what are otherwise "public" APIs (see e.g. the MP's non-OPTIMADE API)....

Could we get away with defining a new enum value in `structure_features` for this?

> Following the discussion with @sauliusg I can also point out many edge cases where the `experimental` or `theoretical` nature is not immediately clear. An example is de-novo crystal structure...