ShowCellBracket is an option for Cell that specifies whether to display the bracket that indicates the extent of the cell.
ShowSelection is an option to Notebook, Cell, and Style that specifies whether to show the current selection highlighted.
SignPadding is an option for NumberForm and related functions that specifies whether padding should be inserted after signs.
StreamPosition[stream] returns an integer that specifies the position of the current point in an open stream.
Streams
(Built-in Mathematica Symbol) Streams[] gives a list of all streams that are currently open. Streams["name"] lists only streams with the specified name.
TargetFunctions is an option for functions such as ComplexExpand that specifies what functions to attempt to generate in the output.
TooltipDelay is an option for objects such as Tooltip that specifies how long to delay after the mouse is over the object before displaying the tooltip.
ValidationLength is an option to FindSequenceFunction and related functions that specifies the number of elements in the input sequence that should be used to validate a ...
Word
(Built-in Mathematica Symbol) Word represents a word in Read, Find, and related functions.
$AssertFunction specifies a function to apply to assertions that fail.