How does ISO 8211 relate to SDTS?
ISO 8211 and SDTS are independent standards. ISO 8211 is a “general purpose” data exchange standard that can be used to transfer data and its description (labels and formats) between different computers and software packages. SDTS is an “application-specific” exchange standard intended for geographic and cartographic spatial data. SDTS uses ISO 8211 as its format level. SDTS Part 3 describes how an SDTS transfer is created using ISO 8211 files and structures. The files of an SDTS Transfer have the extension “.DDF” which stands for a “Data Descriptive File”. This term comes from the title of the ISO 8211 standard.
