Collect
(Built-in Mathematica Symbol) Collect[expr, x] collects together terms involving the same powers of objects matching x. Collect[expr, {x_1, x_2, ...}] collects together terms that involve the same powers ...
CopyFile["file_1", "file_2"] copies file_1 to file_2.
DefaultDuplicateCellStyle is a notebook option that specifies the default style to use for cells created by automatic duplication of other cells in the notebook.
DefaultFieldHintStyle is a low-level option for InputField that specifies the default style to use for displaying the field hint.
DelimiterMatching is an option for selections that specifies whether an opening delimiter will match only its respective closing delimiter or any closing delimiter.
DialogSymbols is an option for Dialog which gives a list of symbols whose values should be localized in the dialog.
Element
(Built-in Mathematica Symbol) Element[x, dom] or x \[Element] dom asserts that x is an element of the domain dom. Element[{x_1, x_2, ...}, dom] asserts that all the x_i are elements of dom. Element[patt, ...
EndDialogPacket[integer] is a MathLink packet indicating the end of the Dialog subsession referenced by integer.
End
(Built-in Mathematica Symbol) End[] returns the present context, and reverts to the previous one.
ExponentStep is an option for NumberForm and related functions that determines in what steps exponents are taken to increase when scientific notation is used.