Spatial Referencing by Coordinates provides the new CTS interface specification. Java interfaces are defined by [GEOTOOLS:GeoAPI] and implemented in org.geotools.referencing.*.
The ISO and OGC are working together on this specification, so the following document is ISO 19111.
- Topic 2 - Spatial Referencing by Coordinates - http://www.opengis.org/docs/03-073r1.zip