SpanFromLeft is a symbol that can appear at a particular position in a Grid or related construct to indicate that the corresponding position is occupied by a spanning element ...
StabilityMargins is an option to frequency response plots such as BodePlot, NyquistPlot, and NicholsPlot that specifies the gain and phase margins to be shown on the plot.
Stack
(Built-in Mathematica Symbol) Stack[] shows the current evaluation stack, giving a list of the tags associated with evaluations that are currently being done. Stack[pattern] gives a list of expressions ...
StatusArea[expr, string] displays string in the status area of the current notebook when the mouse pointer is in the region where expr appears.
TextAlignment is an option for Cell, Style and related constructs which specifies how successive lines of text should be aligned.
TextCell["string"] gives a text cell that can appear in a Mathematica notebook.TextCell["string", " style"] gives a text cell with the specified style.
TextureCoordinateFunction is an option to Plot3D and similar functions that specifies a function that computes texture coordinates.
ToCharacterCode["string"] gives a list of the integer codes corresponding to the characters in a string. ToCharacterCode["string", " encoding"] gives integer codes according ...
TopHatTransform[image, ker] gives the morphological top-hat transform of image with respect to structuring element ker.TopHatTransform[image, r] gives the top-hat transform ...
TopologicalSort[g] gives a list of vertices of g in topologically sorted order for a directed acyclic graph g.