Short descriptions in LwDITA

Dear Lightweight DITA subcommittee members,
We didn't have time in yesterday's call to talk about an issue that has been buried in the agenda for a few weeks.  As I work on the committee note and detail (used as a verb here) the list of DITA elements in LwDITA and their equivalents in XDITA, HDITA, and MDITA, I go back to the question about shortdesc and how to represent it across our authoring formats.  In the initial MDITA draft I proposed to Michael back in... ooops... 2014??... shortdesc did not exist, and the first paragraph in a Markdown file was by default treated as a short description.  Then, Jarno asked "What if the topic only consists of one long paragraph?" and we decided to keep things simple and use "raw" HTML/HDITA in MDITA for elements that do not exist in Markdown but would be ok with CommonMark.  As a result, now a short descriptions is <p data-hd-class="shortdesc"> both in HDITA and MDITA.  Question:  - Should we go back to just treating the first paragraph in MDITA as a short description?  - If we do that, do we really need <p data-hd-class="shortdesc"> in HDITA (HTML5?)  - And do we even need that in XDITA as <shortdesc> if we are just defaulting to first paragraphs?
Best,
Carlos

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Carlos Evia, Ph.D.  Director of Professional and Technical Writing  Associate Professor of Technical Communication  Department of English  Center for Human-Computer Interaction  Virginia Tech
Blacksburg, VA 24061-0112  (540)200-8201