FilterRules[rules, patt] filters the list rules by picking out only those rules whose left-hand sides match patt.FilterRules[rules, {patt_1, patt_2, ...}] picks out rules ...

FontColor is an option for Style, Cell, and related constructs that specifies the default color in which to render text.

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.

ImageSizeAction is an option for Pane and related constructs that specifies what to do if the specified ImageSize setting does not match the size of the contents.

MaxExtraBandwidths is an option to SmoothKernelDistribution that controls the behavior outside that data range.

MessageList[n] is a global object assigned to be a list of the names of messages generated during the processing of the n\[Null]^th input line.

NotebookDelete[notebook] deletes the current selection in the notebook corresponding to the specified notebook object. NotebookDelete[] deletes the current selection in the ...

Null is a symbol used to indicate the absence of an expression or a result. It is not displayed in ordinary output. When Null appears as a complete output expression, no ...

expr >>> filename appends expr to a file. PutAppend[expr_1, expr_2, ..., " filename"] appends a sequence of expressions expr_i to a file.

RowsEqual is an option for the low-level function GridBox that specifies whether all rows in the grid should be assigned equal total height.