NumberForm[expr, n] prints with approximate real numbers in expr given to n-digit precision.
OneIdentity is an attribute that can be assigned to a symbol f to indicate that f[x], f[f[x]], etc. are all equivalent to x for the purpose of pattern matching.
Operate
(Built-in Mathematica Symbol) Operate[p, f[x, y]] gives p[f][x, y]. Operate[p, expr, n] applies p at level n in the head of expr.
OwnValues[x] gives the rule corresponding to any ownvalue defined for the symbol x.
RogersTanimotoDissimilarity[u, v] gives the Rogers\[Dash]Tanimoto dissimilarity between Boolean vectors u and v.
RotateRight[expr, n] cycles the elements in expr n positions to the right. RotateRight[expr] cycles one position to the right. RotateRight[expr, {n_1, n_2, ...}] cycles ...
ScientificForm[expr] prints with all real numbers in expr given in scientific notation. ScientificForm[expr, n] prints with numbers given to n-digit precision.
SetSharedFunction[f_1, f_2, ...] declares the symbols f_i as shared functions whose downvalues are synchronized among all parallel kernels.
SpellingOptions -> {opt_1 -> val_1, opt_2 -> val_2, ...} is an option for notebooks that specifies settings for spell checking.
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 ...