Get Departure decision on whether to put language_tag in returned Location headers

We occasionally return an object AND a location header specifying the object's location. Is that kosher?

Our location headers don't specify a language_tag, and thus aren't usable directly as URLs because the language_tag has to be appended. It's true that the language_tag isn't part of the object, but it's unclear how location headers are supposed to be used. Let's look up best practices on this.

Start by locating the API handlers that return both an object and a Location header, then review how those headers currently represent language_tag. Compare the available URL forms and record the project's decision on whether language_tag belongs in returned Location headers; done means the behavior is decided and the affected API responses are consistent.

Written by the indexing model from the issue text.