In T71689: Entering ";" does not trip the wikitext warning that it won't work (i think?) it was decided to make : result in a <blockquote>, instead of <dd>.
There's some concern that having : result in different outcomes in wikitext vs visualeditor (<dd> vs <blockquote>) is confusing to editors, particularly in the context of Flow.
| Status | Subtype | Assigned | Task | ||
|---|---|---|---|---|---|
| Stalled | None | T151854 VisualEditor hardly usable for talk and discussion pages | |||
| Open | None | T112690 Reconsider that typing ':' at the start of a paragraph in VisualEditor creates a <blockquote>, not a <dd> which is the wikitext equivalent |
I submitted the report on DannyH's page. However colon was merely used as an example.
The real issue is that Flow is tries to incorporate incoherent sets of semantics in the same post. It would take a close examination of the parser(s) to identify all of the differences. Just as an example, one set of semantics supports nesting of :*# (this is the semantics matching Article pages), and the second set of semantics appears to have no support for nesting.
I've been submitting a whole pile of bugs, and it seems most of them trace back to this awful kludge of mixing incompatible semantics in the same post. Copy paste mangles content, reverting an edit mangles content, merely clicking </> twice can mangle things.
I'm entirely OK with making : insert a <dl><dd> when that functionality is available (though really the user almost always wants to indent, rather than make a list of definitions, so…), but whilst it's unavailable I think this is a reasonable alternative.
Here's an edit where a user editing using VisualEditor accidentally indented their comment with a blockquote tag: https://pl.wikipedia.org/?diff=64890039
(I found this because https://pl.wikipedia.org/?diff=64890286 came up in dtcheck)