I've seen a few duplicates like this question, but not exactly this question, so I'm going ahead and asking this.
As mentioned in the title, it's possible to create [custom](http://links.to.websites) in Markdown in comments, but I personally prefer using HTML globally because of its declarative, slightly more consistent behavior (just glance in the direction of the the ≳4294967296 "Markdown broke on my post / in <specific situation>!!1" questions on here) - and I often forget I can insert custom-titled (ie non-bare) links in comments because of this fact.
It'd be really nice to have this behavior, and equally nice if HTML/Markdown markup didn't add to a post's character count, too, which would go a long way toward making HTML/Markdown formatting a personal preference and not a system requirement to pack the most into posts. (Also, I'm not seeing the character limit boost mentioned in the link.)