Board Thread:Support Requests - Getting Technical/@comment-30503377-20160911013206/@comment-1757994-20160911052617

HTML tables support the  element, which allows you to set attributes on groups of columns. However, MediaWiki does not support  in wikitext markup. If you really wanted it, you could insert it with JavaScript after page load. But if you're using JavaScript to set attributes, you might as well just loop down the cells in a column.

I'm not sure what you mean by a hidden comment, but CSS supports the  pseudo-selector. You can change the attributes of a cell based on that, including content.

A drop-down list would require JavaScript to insert, since there's no  markup in wikitext, but it can be done.