A method, system and article of manufacture for generating a logical field
specification for a logical field associated with a physical entity of
data in a computer system, the physical entity of data having a
particular physical data representation, the method comprising: providing
a logical field specification template comprising a plurality of
specification sub-fields, each specification sub-field designated by a
sub-field descriptor; accessing the physical entity of data to determine
data items associated with the sub-field descriptors; and linking each
specification sub-field to a corresponding determined data item.