That's kinda cool but the article addresses a major concern with this strategy that is not addressed here. Which is that many of these tags (e.g. <special>, <keyword>, etc) might someday become part of the HTML standard.

The article states that anything with a dash is guaranteed not to be and another commenter here shared their strategy that involved a naming convention like <x-special>, <x-symb>, etc. Perhaps substituting x for j would make sense and alleviate the concern of possible future clashes with web standards

Fair, I had a collision with <math> for a month before someone else noticed some minor error.