Finally!  Found the answer in 12.6.5 of the manual:

    Here is line the long line */@@html:<br>@@

/*I had tried the '@@' but did not put the "html:".  Hope this helps
someone else.

--dag

On 09/20/2016 05:28 PM, David A. Gershman wrote:
> I'm struggling trying to get an .org file exported and showing how I
> typically structure my HTML results.  At this point, I'm trying to
> figure out how to get a "<br>" inserted to force continuation on the
> next line.
>
> My org file has:
>
>     This is line one.
>     This is line two.
>
> but the HTML export makes them different paragraphs...which is what I
> utilize.  However, a separate portion of my file has a long line and I
> do /not/ want a new paragraph, just to force a <br>:
>
>     This is a long line for which I want to simply, at some point,
>     start the rest on the next line.  Not a separate paragraph.
>
> With Babel, we can do things like /src_perl{#code}/ for inline code
> execution, but what about substitutions like HTML where code isn't
> executed?
>
> TIA.
>
> --dag