r with dot below is defined as a combined glyph: http://www.fileformat.info/info/unicode/char/1e5b/index.htm  Similarly r + line below.  

But ring below is - as you observe correctly - not in the unicode standard as a single glyph.  See, e.g., this list.  The letter r + ring below is, as others have said, still fully achievable and fully Unicode, but it has to be rendered with a combination of the two glyphs r and the non-spacing ring below.

The canonical list of names from the Unicode website is here: http://unicode.org/charts/charindex.html .  Search for "ring below" to see what is, and what isn't available.

Best,
Dominik

​
--
Professor Dominik Wujastyk
​,​

Singhmar Chair in Classical Indian Society and Polity
​,​

University of Alberta, Canada
​.​

South Asia at the U of A:
 
​sas.ualberta.ca​
​​


On 16 January 2017 at 08:22, Gruenendahl, Reinhold via INDOLOGY <indology@list.indology.info> wrote:
Dear list members,
I would be much obliged for any information concerning the current HTML definitions for (vocalic) r, R, l, and L, long and short, with underring (not underdot).
The definitions I found some years ago (e.g., &#59444; for R-underring and &#59445 for r-underring) do not seem to be valid anymore.
I have searched Alan Wood's site, but in vain.

Thanks in advance
Reinhold Grünendahl

_______________________________________________
INDOLOGY mailing list
INDOLOGY@list.indology.info
indology-owner@list.indology.info (messages to the list's managing committee)
http://listinfo.indology.info (where you can change your list options or unsubscribe)