What exactly is Custom Coding criterion?

[Jogo]

The issue is that modern CMSs like Wordpress, Drupal, Joomla, etc. are much more than CMSs--they have pre-built templates and add-ons that make it possible to build a highly-functional website while knowing nothing at all about web design or programming. This is where teams get into trouble, and have websites that appear too polished/safe/professional, and look almost "factory-made".

My advice is to use a CMS, but only rely on the most basic features. That is, design your own template in HTML, CSS, and Javascript, and maybe even try to program your own calendar, image gallery, video gallery, etc. You will learn the most this way IMO, and will more than satisfy the criterion on the rubric.