X-Frame-Options header

software development

#1

I’m trying to use X-Frame-Options headers on one of my sites. I tried the following in .htaccess:
Header always append X-Frame-Options SAMEORIGIN
(suggested on Mozilla’s site)

and

Header set X-Frame-Options “DENY”
(suggested on Dreamhost Wiki)

But neither of them seems to show in headers when I check them with the Firefox web developer extension.

What is the proper way to set this option in .htaccess?
Thanks in advance and Happy Easter to who celebrates it.