JabRef version 3.4
Isbn should be ISBN (https://en.wikipedia.org/wiki/International_Standard_Book_Number)
Doi should be DOI (https://en.wikipedia.org/wiki/Digital_object_identifier)
see screenshot

URL, URI, ISSN are also candidates for other casing.
Maybe we should display the fields as we currently write them out:
everything in lower case.
Would that also be fine with you?
isbn, doi, url
Why not write it in their correct spelling? I am not in the development team, so I do not have the right to decide about spellings, but to my understanding it would be very logical to write things as they are written. Please correct me, if I miss some obvious point here. Best regards, Jonas
Implemented and merged with #1589
Most helpful comment
Why not write it in their correct spelling? I am not in the development team, so I do not have the right to decide about spellings, but to my understanding it would be very logical to write things as they are written. Please correct me, if I miss some obvious point here. Best regards, Jonas