[Proj] esri shape files

[support.mn at elisanet.fi]

Frank Warmerdam [warmerdam at pobox.com] kirjoitti: 
> Please don't just dump not-quite-ESRI WKT into the .prj
> file.  It will mess me up!

mess it seems to be already if you read this text:

http://home.gdal.org/projects/opengis/wktproblems.html

I have never really understood why they have to put parameter
names in the definition files?! or indexes pointing to unknown
definitions?

That will just mess it up, since nobody will never know what
additional names and definitions will be generated later and
by all current instances. The only way to handle that is to put
directly the parameter value or index value in the file and never
use names as values or indexes to something.

That is the reason why proj.4 definitions are much more power
full than for example WKT or GeoTiff. Take for example the
"towgs84" statement. It can define any current and future datum
accurately without the need to rewrite the programs or data files
all over again when a single new datum is created.

Put if your put there "datum=MyStrangeDatum31221341" it is
clear that nobody will never be able to use that file for anything
since they simply will never be able to figure out what was or is
"MyStrangeDatum31221341".

Regards: SL