SusiQ takes all its information from several definition files. All of them are ordinary ASCII files, which makes them easy to modify. All the definition files have a common organisation. They are each divided into two sections delimited by an "=" (equal sign) in the first column. Any text prior to the equal sign is regarded as a comment (with the exception of the constant file file.CST see this section) . After the equal sign, SusiQ expects to see a known command and will attempt to interpret the string as a valid instruction. The "!" (exclamation mark) can be used anywhere in the second section to comment out any string placed on it's right hand side.