SameTest is an option whose setting gives a pairwise comparison function to determine whether expressions should be considered the same.

ShowClosedCellArea is an option for cells that specifies whether a rectangular bar is displayed next to a closed cell group to indicate the number of cells in the group.

ShowPageBreaks is a notebook option that specifies whether to indicate in the on-screen display of a notebook where page breaks would occur if the notebook were printed.

StringCount["string", " sub"] gives a count of the number of times " sub" appears as a substring of " string". StringCount["string", patt] gives the number of substrings in " ...

StringToStream["string"] opens an input stream for reading from a string.

Stub is an attribute which specifies that if a symbol is ever used, Needs should automatically be called on the context of the symbol.

StyleBoxAutoDelete is an option for selections that specifies whether a StyleBox wrapped around them should be automatically removed when the expression is edited.

SyntaxPacket[integer] is a MathLink packet where integer indicates the position at which a syntax error was detected in the input line.

Together[expr] puts terms in a sum over a common denominator, and cancels factors in the result.

Visible is a notebook option which specifies whether the notebook should be explicitly displayed on the screen.