DamerauLevenshteinDistance[u, v] gives the Damerau\[Dash]Levenshtein distance between strings or vectors u and v.
DistributionParameterQ[dist] yields True if dist is a valid distribution, and yields False otherwise.
GroupCentralizer[group, g] returns the centralizer of the element g in group.
Kernels
(Built-in Mathematica Symbol) Kernels[] gives the list of running kernels available for parallel computing.
MaxRecursion is an option for functions like NIntegrate and Plot that specifies how many recursive subdivisions can be made.
PaletteNotebook[{cell_1, cell_2, ...}] represents a palette notebook that can be manipulated by the Mathematica front end.
PlotMarkers is an option for graphics functions like ListPlot and ListLinePlot that specifies what markers to draw at the points plotted.
Print
(Built-in Mathematica Symbol) Print[expr] prints expr as output.
PropertyList[{obj, item}] lists the properties available for item in obj.
Shortest[p] is a pattern object that matches the shortest sequence consistent with the pattern p.