As the WFC software utilizes the parameter passing system of the 'ftools' package also the following shell environment variables are required: > setenv FTOOLDIR /ftools/distribution that holds all relevant subdirectories. Some of the subdirectories may also a subdirectory of the FTOOLS structure (e.g. saxwfc). A program is invoked in the following form => program-name par-value1 ... par-value# [option1] [option2] ... [option#] where option can either be [option-name] or [option-name=value] where values may be either a string (with or without quotes), an integer, a real, a boolean (only yes or no are accepted) Parameters are position dependent, but can be placed anywhere in the runline by the [parname=par-value] construct. In order to enable the tracing back of the data flow the parameters that control the processing options will be stored in all resulting files. These parameters will be stored as keywords into the Primary Header of an FITS output file. The following general parameters are the same for all of these programs. a. verbsty=integer The number controls the volume of the output to STDOUT The higher number the more information about the processing is given. If 0 there will be minimal output; only signalling the starting end the stopping of the program and warnings will be output plus additional information on fatel errors that may occur. b. title=string Option to insert user defined text as a parameter keyword into the fileheader c. blockio=boolean If 'no' use is made of block reads or writes to or from the file. The advantage is much faster I/O times than when using the standard ftools/fitsio routines. The drawback is that files created in that way may not be compatible with those on different com[puter systems and that adding columns in a file needs modifying all the programs that read or write such a file.