HoldAll
(Built-in Mathematica Symbol) HoldAll is an attribute which specifies that all arguments to a function are to be maintained in an unevaluated form.
HoldComplete[expr] shields expr completely from the standard Mathematica evaluation process, preventing even upvalues associated with expr from being used.
HoldFirst is an attribute which specifies that the first argument to a function is to be maintained in an unevaluated form.
HoldPattern[expr] is equivalent to expr for pattern matching, but maintains expr in an unevaluated form.
HoldRest is an attribute which specifies that all but the first argument to a function are to be maintained in an unevaluated form.
HotellingTSquareDistribution[p, m] represents Hotelling's T^2 distribution with dimensionality parameter p and m degrees of freedom.
HoytDistribution[q, \[Omega]] represents a Hoyt distribution with shape parameter q and spread parameter \[Omega].
Hue
(Built-in Mathematica Symbol) Hue[h] is a graphics directive which specifies that objects which follow are to be displayed, if possible, in a color corresponding to hue h. Hue[h, s, b] specifies colors in ...
HyperbolicDistribution[\[Alpha], \[Beta], \[Delta], \[Mu]] represents a hyperbolic distribution with location parameter \[Mu], scale parameter \[Delta], shape parameter ...
HypercubeGraph[n] gives the n-dimensional hypercube graph Q_n.