FieldSize is an option for InputField, PopupMenu, and related functions that specifies the size of the field allowed for input or contents.
FourierSequenceTransform[expr, n, \[Omega]] gives the Fourier sequence transform of expr.FourierSequenceTransform[expr, {n_1, n_2, ...}, {\[Omega]_1, \[Omega]_2, ...}] gives ...
FractionBox[x, y] is a low-level formatting construct that represents x/y in notebook expressions.
FrameMargins is an option for objects that can be displayed with frames which specifies the absolute margins in printer's points to leave inside the frame.
FunctionSpace is an option for FindSequenceFunction and related functions that specifies the space of functions to consider for representations.
GeoDirection[{lat_1, long_1}, {lat_2, long_2}] gives the azimuthal direction from one latitude-longitude position on the Earth to another.GeoDirection[pos_1, pos_2] gives the ...
GeoDistance[{lat_1, long_1}, {lat_2, long_2}] gives the geodesic distance in meters between latitude-longitude positions on the Earth.GeoDistance[pos_1, pos_2] gives the ...
GraphLayout is an option to Graph and related functions that specifies what layout to use for graph components and collections of components.
GroupOrder[group] returns the number of elements of group.
Heads
(Built-in Mathematica Symbol) Heads is an option for functions which use level specifications that specifies whether heads of expressions should be included.