The SIF decoder depends on user-modifiable variables, which are not directly included in the Fortran source code, but cast prior to compilation. The file containing the user-modifiable data is sifdec.siz. After the initial installation, this file will be in the SifDec directory $MYSIFDEC/[single|double]/config. If modified, the SifDec distribution may be rebuilt using the new parameter values using make.
Some Fortran source files, like clsf.f and slct.f, have hardcoded user-modifiable parts. These are usually located at the top of the file, between banners, such as
and