SetSystemOptions["name" -> value] resets the value for the internal system option with the specified name.
ShowStringCharacters is an option for Cell that specifies whether to display " when a string is entered.
ShrinkingDelay is an option for dynamic objects that specifies how long to delay before shrinking the size of the region in which the object is displayed to the actual size ...
Skeleton[n] represents a sequence of n omitted elements in an expression printed with Short or Shallow. The standard print form for Skeleton is <<n>>.
StackComplete[expr] evaluates expr with intermediate expressions in evaluation chains included on the stack.
StreamColorFunctionScaling is an option for graphics functions that specifies whether arguments supplied to a stream color function should be scaled to lie between 0 and 1.
TimeZone is an option for DateString, AbsoluteTime, and related functions that specifies the time zone to use for dates and times.
VectorColorFunctionScaling is an option for graphics functions which specifies whether arguments supplied to a vector color function should be scaled to lie between 0 and 1.
$ByteOrdering gives the native ordering of bytes in binary data on your computer system.
$CharacterEncodings gives the list of character encodings that can be used.