InputAutoReplacements is an option for cells and notebooks which specifies strings of characters that should be replaced immediately on input.
PrintAction is an option for notebooks that specifies the action taken when a Print[] command is evaluated by the kernel.
PrintingStartingPageNumber is an option for notebooks that specifies what number to assign to the first page of a notebook when printed.
expr //. rules repeatedly performs replacements until expr no longer changes.
StyleDefinitions is an option for notebooks that gives definitions for the styles that can be used in a notebook.
ViewVertical is an option for Graphics3D and related functions which specifies what direction in scaled coordinates should be vertical in the final image.
WindowTitle is an option that specifies the title to give for a window.
$MaxPrecision gives the maximum number of digits of precision to be allowed in arbitrary-precision numbers.
$ModuleNumber gives the current serial number to be used for local variables that are created.
PieChart[{y_1, y_2, ...}] makes a pie chart with sector angle proportional to y_1, y_2, ....PieChart[{..., w_i[y_i, ...], ..., w_j[y_j, ...], ...}] makes a pie chart with ...