Formatting behavioral data

I have one uncertainty regarding the proper formatting of behavioral data. If I have a task consisting of stimuli/events with a known onset/duration, should I still label them as _beh rather than _events? It seems that validation fails if I have _events files without a corresponding _beh file. At the same time, the instructions: "events files that do not include the mandatory onset and duration columns can still be included, but should be labeled _beh.tsv" suggest that _events is preferred for data with known timings. What would I store in the _beh file if I specify a _events file?

What error is generated when you have everything in the _events.tsv? To confirm is this to store behavioral data in the beh/ directory, or is it to live alongside data from another modality?

In bids-examples only 2 datasets have beh directories. One only has _events.tsv and the other only has _beh.tsv, so there is precedent for both:

should I add this to the synthetic example dataset to have a formal test of this?

Thanks, it works now! I must have messed up somehow and then I read this statement under Task events: “Each task events file REQUIRES a corresponding task data file” and assumed this was the cause.

It makes sense that this requirement is different for beh than physio or func, though.