The Content-Security-Policy HTTP header has a frame-ancestors directive which you can use instead. Note that in the legacy Firefox implementation this still suffered from the same problem as SAMEORIGIN did - it doesn't check the frame ancestors to see if they are in the same origin. In supporting legacy browsers, a page can be displayed in a frame only on the specified origin uri. This is an obsolete directive that no longer works in modern browsers. Also see Browser compatibility for support details. The spec leaves it up to browser vendors to decide whether this option applies to the top level, the parent, or the whole chain, although it is argued that the option is not very useful unless all ancestors are also in the same origin (see bug 725490). The page can only be displayed in a frame on the same origin as the page itself.
The page cannot be displayed in a frame, regardless of the site attempting to do so. On the other hand, if you specify SAMEORIGIN, you can still use the page in a frame as long as the site including it in a frame is the same as the one serving the page. Eliminate data-entry, and conveniently get the financial reports you need, so you can spend more time doing what you love.
If you specify DENY, not only will the browser attempt to load the page in a frame fail when loaded from other sites, attempts to do so will fail when loaded from the same site. Accounting that’s seamlessly integrated with invoicing, receipt scanning, payment processing, and payroll.
