The 1. vs non 1. list starts are not intuitive at all when it comes to sub lists.
2. item 1
1. item 2
1. item 2.1
1. item 3
2. item 3.1
The third item’s sub item starts with 2. and will not be a sub-item, but part of the item 3 text in commonmark:
<li>item 3 2. item 3.1</li>
Meanwhile the expectation and how other implementations treat it is as a sub-item BabelMark2 example.
This rule of only ordered items numbered 1. can break paragraphs, only partially addresses breaking a paragraph by an ordered list and happens to break compatibility of sub-lists starting without a blank line in parent items unless the sub-list numbering starts with 1. I think the latter is very unintuitive. It effectively means that if you want an ordered list item without a blank line before you must start it with 1., everywhere.
I am against lists breaking regular paragraphs because this can happen inadvertently when a paragraph is wrapped and would make list items not break paragraphs unless that paragraph is another list item’s first paragraph, i.e. the one corresponding to the item’s text. No other restrictions.
This would eliminate any inadvertent lists (of any type or numbering) in paragraphs to match other markdown implementations and allow any numbered ordered sub-list to be the first item. The only cost of that is a blank line between a paragraph and a list. This is nothing new and most markdown users already expects this, unless they are used to GFM only. It is also a much cleaner solution than either escaping potential list starts from paragraphs or having to scan your document just in case an inadvertent list item was injected into the document. All that just to avoid a blank line between a list and a paragraph. Which most other processors require: Babelmark2
I was caught by this just now. I was not getting the sub-item as expected only to realize after wasting a lot of time debugging code that it was numbered 2. instead of 1. This is completely outside what is expected from Markdown sub lists and very unintuitive, IMO.