What I've gleaned over the years is that LJ is custom software,... Woodknack
Good Heavens! Why on earth would they (Verticalscope) use custom software? There are dozens of really good open source content management systems with considerably more features than this site. And they wouldn't have to maintain the base code.
So, who or what is Verticalscope? What they aren't is a software platform. The few sites I browsed have a wide variety of underlying engines including a few OS forums and at least one Joomla (OS CMS) site. They are, it seems, an advertising company of sorts based in Canada. Their business model is to acquire successful community domains and monetize them with ads. Their value to LJ is they eat the hosting costs. Nothing particularly wrong with that, I suppose. However, expecting any sort of support beyond basic site maintenance and issues affecting ad revenue might be a bit of a reach.
This site appears to be a host served dynamic page system, pretty much a classic content management system strategy. I'm guessing a PHP/MySQL server on the host side. The actual content resides on the server. Browsers request a page, the server software fetches the appropriate data, formats the page and sends it back. Real last century stuff.
Typically, there's a privileged admin function to allow for site management including editing any and all content. At least that's what the vast majority of CMS systems do. So, saying it's buried in the code either isn't true or LJ is in dire need of a new engine on the back end. There isn't anything on this site that WordPress (the elephant in the room) couldn't do along with a lot more. And instead of a 200 person company, WP has several thousand people maintainig the base code.
PS. The help page remains unchanged.