I've already discussed this with Mark offlist and he (at leastYup. It looked right (plain and simple HTML blockquote element) when I took a look at the View Source of some messages.
I think he implied it's up to the app to make theIndeed. And we're seeing that different interfaces treat it differently.
I did emphasize that the odd thing is that this is not a problem ifThat doesn't seem odd to me at all.
The blockquote feature we're talking about is an HTML element. When a user sends a plain text message, or the group checks the Plain Text Only box, then the whole question of blockquote formatting doesn't apply.
Then the only question is whether the mail interface does something "clever" with the left-margin > marking which is the plain-text convention for marking quotes.
The email standard for "flowed text" allows the email interface to re-word-wrap blocks of quote-marked text. The Groups.io web interface goes a step further and converts them back to HTML blockquote elements.
So knowing that's the case, I wonder if that can be faked-out byAll sorts of fakery is possible, but not necessarily wise.
Going beyond putting style controls on the blockquote element, Groups.io could replace the blockquote element with other formatting elements in an attempt to simulate what we think blockquote should look like. But "that way lies madness", I think.