I am developing a web api which will accept text/csv data. The users are international and may want to supply dates or numbers in the language of their country, so I need the API to be aware of the language the input is in.
Looking at the Content-Language header, this is used
to describe the language(s) intended for the audience, so that it allows a user to differentiate according to the users' own preferred language.
But I can only find references to this in the context of the response from the server where I want to specify the language of the request.
I haven't seen anything specifically disallowing this header on a request but I cannot find any examples of same.
I also looked at the Accept-Language header but that specifies the language you would like the response to be in so is not suitable in this case.
I could create a custom header for this purpose but would prefer to stick to standards where possible.