Indicates the models
that are to be written out. It should be a comma separated list of model names (e.g. COM, FLT, AST,
RES, etc) contained within parentheses, or a single model name. A model name of RES here refers to
the residuals after subtraction of all models in use (typically COM, FLT and AST). The residuals can
also be written out at other times - see diag.res_before and diag.res_after. Only used if a value is
supplied for parameter
"diag.out" . [(com,ext,flt,ast,res)]