I’m bumping this topic because I just got surprised at the change in the spec in 0.24. Pointy brackets are no longer allowed in urls, and therefore image paths.
http://spec.commonmark.org/0.24/#example-455
And from this discussion: Issues we MUST resolve before 1.0 release [6 remaining] - #13 by codinghorror
Inconsistent handling of spaces in links
<http://example.com/hey nice link>
There’s a very well understood way to encode spaces into links, our old pal %20 and spaces in links are some bad mojo anyway that we should not be encouraging. We should not allow spaces in links.
The issue for me is that now it’s much more difficult to add a reference to an image file on disk. It’s very common to have image names that have spaces in them (even macOS creates their screen shots named “Screen Shot 2017-08-05 at 11.07.11 AM.png” for example).
And while we could ask the user to replace each space with a ‘%20’, that seems excessive and unfriendly. I thought enclosing the url in pointy brackets was a workable, if not obscure, way of solving the problem ( I would have preferred to enclose the url in quotation marks, because I think that is more intuitive, but maybe conflicted in other situations).
So…i’m advocating for pointy brackets to return for urls. I agree percent encoding is better in general, but I also think it’s unfair to force a user to do it themselves when writing a plain text document.