CPL functions for Data Flow System compatibility

 The functions of this library ensure the compliance of pipeline
 products with the Data Flow System (DFS) of the European Southern
 Observatory (ESO).
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 The Common Pipeline Library (CPL) comprises a set of ISO-C libraries that
 provide a comprehensive, efficient and robust software toolkit. It forms a
 basis for the creation of automated astronomical data-reduction tasks (known
 as "pipelines").