One useful means of keeping track of user-specified runtime options is use of -optionstable, which prints to stdout during PetscFinalize() a table of all runtime options that the user has specified. A related option is -optionsleft, which prints the options table and indicates any options that have not been requested upon a call to PetscFinalize(). This feature is useful to check whether an option has been activated for a particular PETSc object (such as a solver or matrix format), or whether an option name may have been accidentally misspelled.