Definition description without a term is read back as text or as a code block in CommonMark Markdown 1.2

Markdown definition descriptions need a term. When rendering to markdown/1.2 a description without a term located in a list item or nested in another description, it's not read back as a description:

• xhtml/1.0 <ul><li><dl><dd>d</dd><dd>e</dd></dl></li></ul>: read back with a term : d (text).
• xwiki/2.1:

  ; t
  :: d
  

  is rendered as

  :   t
  
      :   d
  

  and the nested description is read back as a code macro containing : d.

Expected: the descriptions are read back as descriptions (or at least as their text, never as a code block).
Note: MARKDOWN-130 covers a related case (description rendered on the same line as the preceding content).