[georss] [Context.RWG] Non compliant services in Context

[Martin Daly]

> Another aspect of the tiling scheme would be the generation 
> of lookup tables / registers which link each tile to its 
> geographic bounding box in each CRS of interest (starting of 
> course with EPSG:4326 / WGS84). This has the interesting side 
> effect of defining valid extents for projected coordinate 
> systems such as UTM  and State Plane.

Why "starting of course with EPSG:4326 / WGS84"?  And good luck with
that lookup table/registry "in each CRS of interest", by the way.

Up front I have to say I'm a bottom-upper, not a top-downer in this.
The vast majority of data that we see is not geographic, but projected,
and then typically has a very specific target scale, or range of scales.

To come over all parochial, OS MasterMap Topography Layer is typically
displayed or printed (we still do that over here) at 1:1250, 1:2500 or
1:10000 precisely, for urban, rural and mountain/moorland respectively.
Try getting to that precise scale with a top-down tiling scheme.

M