User blog comment:LS11sVaultBoy/GTA Wiki Weekly News - 27th August 2016/@comment-25295528-20160828185635/@comment-30221114-20160831162759

Custom Javascript enables custom Wikia Rail Modules, to which it requires a template (Template:RandomModule) to display content. The Modules themselves can be modified via JS and CSS, whereas the content within them is edited in the template. Pretty simple, I had expected you would've already known this sort of stuff to be honest.