[South Florida DX Association] What's the reason for the "R" prefix?

[Bill]

 From another list:

The Royal Wedding - http://www.rsgb.org/news/articlelinks.php?id=0123
K2DSL - David



On Sat, Apr 30, 2011 at 11:36 PM, Mike<k4gmh at arrl.net>  wrote:
>  Hello,
>  Worked several G stations with familiar call signs except for the
>  additional
>  "R" in the prefix.  What is the occasion for the "R"?
>  --
>    73,
>    Mike, K4GMH