HN as is does not reliably detect duplicates even with query parameters untrimmed; see the point above about ?id=123&comments=1 and ?comments=t&id=123. Further,

HN as is does not reliably detect duplicates even with query parameters untrimmed; see the point above about ?id=123&comments=1 and ?comments=t&id=123. Further, even if there was an exact match on the query params in a certain order, the REST standard makes no guarantee on what resource(s) are returned on subsequent identical calls such as when an addition is added with ?topic=Conjecture or ?topic=Theorem as they are by design meant to indicate the uses like filtering or sorting. So, it's not possible to rely on identical uniform resource locators with query params to detect duplicate resources. It would be an incentive for those sites that want to be able to have more frequent visibility of specific resources on aggregator sites with duplicate detection to conform to the standard. Note detection != blocking. Those non-conforming are not being forced to change and it could be argued that visibility would be enhanced by preventing ambiguity of discussion on specific resources. If the title is set as required at the time of submission, then that field could be different and as discussed above any set of relevant URLs with query params could be added to the text field to specify resource(s) on a non-conforming site to bypass a duplicate check along with a [suggested not required] helpful description of what was seen at any query param URL at the time of submission. Obviously, the resources at non-query param URLs may change too depending on the whims of a site owner, but are suppose to be unigue resource IDs by REST.