New Post: Definition Lists / Description Lists

I'm trying to add definition lists / description lists to the Visual Editor to produce:

<dl>
  <dt>Coffee</dt>
  <dd>Black hot drink</dd>
  <dt>Milk</dt>
  <dd>White cold drink</dd>
</dl> 

I've added the following lines to common.xml:

<format id="dl" label="Def list" image="" notes="" block="dl" classes="" wrapper="1">
  <select />
</format>

<format id="dt" label="Def term" image="" notes="Def term" block="dt" selector="dl">
  <select />
</format>
 <format id="dd" label="Def description" image="" notes="Def description" block="dd" selector="dl">
  <select />
 </format>

But unlike the <div> block containing <p> elements, this doesn't work in the Visual Editor.

Does anyone have any ideas on how to make this work?