Checking the response headers for my website shows this header:
I can't figure out where it's coming from. There is no line in my theme
<?php bloginfo('pingback_url'); ?>. It's not hard-coded in my theme's header.php. I have the XML-RPC setting unchecked in Settings > Writing, and verified that the enable_xmlrpc option is zet to 0 in the wp_options table.
I am using WP-Super Cache and I do notice that in the cache meta files I see this header along with the other headers. I suspect that's just because the header is being sent and would be sent even if WP-Super Cache were turned off.
Any ideas where this could be coming from? I'd like to remove it since I don't use it for anything.