GeoRSS is the encoding of location information is RSS feeds. There are 3 flavors of GeoRSS feeds W3C Basic Geo, Simple, and GML. According to W3C, W3C Basic Geo is for describing points only in WGS84 datum. Examples at http://www.w3.org/2003/01/geo/#example
Simple GeoRSS can be used to describe point, lines polygons and bounding boxes. As with W3C Basic Geo,
Simple GeoRSS uses WGS84 datum in Decimal Degrees (Lat Long). Examples at
http://georss.org/simple.
GML GeoRSS is the most complex encoding format. It can be used to represent
point, lines polygons and bounding boxes in feeds. GML GeoRSS can also use a variety of
Coordinate Systems. Examples can be found at http://georss.org/gml.
References:
GeoRSS :: Geographically Encoded Objects for RSS feeds Fun with GeoRSS - Directions Magazine