Is anyone aware of 'social classification' data sources used, for example, here:

- http://www.checkmyarea.com/EC3N4AB.htm "Wealthy singles in small city flats and suburban terraces"
- http://www.checkmyarea.com/B66HE.htm "Ethnically mixed young families and singles in terraced housing"
- http://www.checkmyarea.com/EH12NG.htm "Suburban scottish households in small terraces and flats"