[rogual]

Thing is, italic and bold don't have just one meaning.

Italic can mean: emphasis, foreign word, word which is being defined for the first time, title of referenced work, mathematical variable, and many field-specific uses.

Bold can mean: strong emphasis, term that needs to stand out and be found easily while scanning, mathematical vector, and again, field-specific uses.

If a markup language only has tags for emphasis and strong emphasis, then you can't put bold or italics for any of the other reasons you might want to use them, so anyone wanting to do those things can only misuse the emphasis and strong-emphasis markup, so it de-facto starts to mean bold/italic anyway.

It's at least reasonable to propose a markup language where you have to say "this is emphasis, this is a foreign word, this is a title of a referenced work," etc. but not everybody is writing a document that needs that much metadata. At least HTML retained <i> and <b> when it introduced <em> and <strong>.

Styles, like words, can have several meanings, and forcing authors to separate them feels a bit like forcing them to write the word "set" differently for each of its 10+ meanings.

[dspillett]

> At least HTML retained <i> and <b> when it introduced <em> and <strong>.

That is not as practical with markdown though, as you are working with a limited set of practical character combinations.

> Styles, like words, can have several meanings

This is one of the reasons why there are many markdown alternatives that behave slightly differently: not everyone writes plain text mark-up with the same intentions.

This isn't something you can solve with a single markdown version, so we have to accept that each could, and probably will, work a little differently.