PGMapCSS is a library for PostgreSQL/PostGIS which works between an osm2pgsql based database and Mapnik (and maybe other renderers). It processes database (usually OpenStreetMap) objects according to MapCSS rules and calculates resulting colors, widths and other properties for Symbolizers, even geometric modifications.
"not" is a prefix for a media query part, but can not be used for single elements. Therefore it's not valid to do @media (user-agent: pgmapcss) and not (min-pgmapcss-version: 0.8).
"not" is a prefix for a media query part, but can not be used for single elements. Therefore it's not valid to do
@media (user-agent: pgmapcss) and not (min-pgmapcss-version: 0.8).