"" Start with an angle bracket, then use the asterisks to italicize and it's readable on mobile/PC and it's clear that you're quoting someone and it's clear what the quoted content is. ""

"What's wrong with quotation marks?"

They get messy, quick.

    ----- BEGIN QUOTATION -----

They get messy quick.

    -----  END QUOTATION  -----

How about this?

That doesn't solve the problem of quoting multiple levels of the thread.

>> This is a time-honored way of identifying a grandparent comment.

    ----- BEGIN QUOTATION: macintux -----

    ----- BEGIN QUOTATION: yellowapple -----

How about this?

    -----  END QUOTATION: yellowapple  -----

That doesn't solve the problem of quoting multiple levels of the thread.

    -----  END QUOTATION: macintux  -----

Hold my beer :)

    ----- BEGIN QUOTATION: macintux -----

>> This is a time-honored way of identifying a grandparent comment.

    -----  END QUOTATION: macintux  -----

Indeed it is, at least in email and Markdown. However, email quotations also usually include the "On $timestamp macintux wrote:" blurb in front to designate who wrote the quotation.

My eyes hurt now.

lol, so do mine. I wouldn't suggest this as an actual quoting method, needless to say. More of a thought experiment around what elements we'd need in a well-designed quoting method.