This version will now construct an output section from more than one input section if necessary. The data control lines are identified by keywords. Only the first 4 letters of each keyword are necessary.
Some data cards are optional.
The program then reads the coordinates to determine the map limits. Symmetry is usually read from the header of the input map so this keyword is not normally needed. Use it only to change symmetry, or if no symmetry is present in the map. This is needed after certain non-CCP4 programs e.g. from Uppsala. Inserts the specified space group symmetry operators into the output map, but does not use them for extending the map.