A standard is proposed describing a portable format for electronic
exchange of data in the physical sciences.   Writing scientific data in
a standard format has three basic advantages: (1) the ability to move
datasets easily from one computing environment to another
(portability); (2) the ability to use location information, processing
notes, and other such meta-data to aid in interpretation of the data
(understandability); and (3) the labor-saving ability to avoid creating
new formats and computer software for each new dataset that comes along
(reusability).  An improperly formulated standard format tends towards
three disadvantages: (1) it can be inflexible and fail to allow the
user to express his data as needed, (2) reading and writing such
datasets can involve high overhead in computing time and storage space,
(3) the format may be accessible only on certain machines using certain
languages, and (4) under some circumstances it may be uncertain whether
a given dataset actually conforms to the standard.

A format has been designed which enhances these advantages and lessens
the disadvantages.  The fundamental approach is to allow the user to
make her own choices regarding strategic tradeoffs to achieve the
performance desired in her local environment.  The choices made are
encoded in a specific and portable way in a set of records.

A fully detailed description and specification of the format is given,
and  examples are used to illustrate various concepts.  Implementation
issues are discussed.