Why there is no markdown for underline?

Question

I am wondering why there is no markdown syntax for underline? I know that basic html tags can be embedded to achieve this but I am trying to understand why underline got omitted when bold and italics exists

Answer 1

There are no mention of "bold" or "italics" in the markdown syntax document. What there is, is an emphasis section, which describes how the use of underscore and asterix -marked spans (*, _, **, __) should produce code wrapped in <em> and <strong> tags.

The reason for this, I presume, is that markdown is a markup language, like html, and should not be concerned with how the text is presented (that's the job of the styling/CSS), but to provide semantic meaning to the text. This is particularly useful for people who use non-graphical browsers, where the emphasis can be conveyed in other ways (Think about how a screen-reader could add emphasis when it encounters an <em> tag, or really add lots of emphasis in the case of the <strong> tag).

I could well use CSS to style my emphasised text with underlines, rather than italics, but this is not the browser default in most cases.