It is inevitable that errors will sometimes be made in constructing and
manipulating the data structures supported by ZEBRA.
In order to allow
a simple and convenient means of checking the integrity of the structures,
including the links and the data, the DZ package has been provided
(see chapter 
).
It has various options to display and validate the whole or part of a dynamic
store.
The DZDOC package contains routines for generating and maintaining documentation
on ZEBRA data structures (see chapter ).
Information about problems or important input/output running
parameters is available in the user communication array
in common /\QUEST/.
In order to have access to the information in this array
the user should include the following definition in his code:
Fortran definition of the user communication vector IQUEST
COMMON /QUEST/IQUEST(100)When a routine detects an error, it identifies itself and gives the case number describing the problem. This number, together with the detailed description of the contents of the elements, will allow the user to trace the problem.
In the case of input/output routines (i.e. the FZ and RZ packages) information about the last operation is available via (see the description of each routine for the meaning of individual values).