I guess it depends on what you consider a default header. (I’m not too familiar with standards here; there may be some IETF definition you’re referring to?)

It turns out if you have enough control over your server you can make it do a lot of things! (Which may or may not conform to a spec.)

Right, but how did you do it? What I was asking for was more details. Now, ever since I wrote my comment, I had the time for a little research and:

$/> curl --head https://ferengi.one

Very cool! Not sure if that's your site but if so, nice work. :)