[MapProxy] Provided Polygons

[Christian Pouwels]

Hello everyone,

I wanted to do some caching for Portugal and Spain and found that it is 
possible to cache inside polygon.
The country borders are already provided 
http://mapproxy.org/static/polygons/ (really nice).
But when configuring the 'seed.yaml' I noticed that I need a polygon_srs.
But I could not find any projection/srs  for the polygons.

So my question is: what is the projection of the provided country polygons.

I feel like I am asking for the obvious but I really cannot find it.

With regards,

Chris