Why does device.device_report_product_code require = rather than :?

Question

To successfully search the device/event endpoint for device.device_report_product_code, you must search using = instead of : like this:

https://api.fda.gov/device/event.json?search=device.device_report_product_code="HQF"

But the API documentation (to my knowledge) doesn't document the required use of = for device.device_report_product_code. Furthermore, if you use : instead of =, you don't get an error. You get "No results found!", which is what this query returns:

https://api.fda.gov/device/event.json?search=device.device_report_product_code:"HQF"

Yet HQF is a valid 3-letter device code. Can someone explain when = must be used and why : (which I thought meant "contains") returned no matches?

Answer 1

This is a very strange bug - the API should be erroring with the use of an equal sign there. We'll open a bug report and investigate. In the meantime, the ':' version does return results and should be what is used.