[whatwg] [mimesniff] The X-Content-Type-Options header

Gordon P. Hemsley gphemsley at gmail.com
Fri Nov 16 14:19:37 PST 2012


Microsoft introduced the X-Content-Type-Options header in IE8 back in 2008:


I would like to integrate the header into mimesniff and describe its
proper usage.

Right now, it allows one parameter: 'nosniff'. I would like to allow
the presence of this parameter to set the 'no-sniff flag' that I just
introduced into mimesniff (in addition to that flag's existing


But I would also like to fully spec the header, while leaving open the
possibility that other values may be added in the future.

In addition, I would like to, if I could, also allow the header to be
specified without the 'X-' prefix (so as 'Content-Type-Options'), for
that reason (and because of best current practice).

Does anyone have any questions, comments, or objections about this issue?

Gordon P. Hemsley
me at gphemsley.org

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