Plus
(Built-in Mathematica Symbol) x + y + z represents a sum of terms.
PodWidth is an option for WolframAlpha that determines the width parameters of the content returned by the Wolfram|Alpha API.
PowerModList[a, s/r, m] gives a list of all x modulo m for which x^r \[Congruent] a^s mod m.
ReleaseHold[expr] removes Hold, HoldForm, HoldPattern, and HoldComplete in expr.
ReturnExpressionPacket[expr] is a MathLink packet that contains the expression expr, the result of an EnterExpressionPacket evaluation.
RowMinHeight is an option for the low-level function GridBox that specifies the minimum total height in units of font size that should be allowed for each row.
RunThrough["command", expr] executes an external command, giving the printed form of expr as input and taking the output, reading it as Mathematica input, and returning the ...
Scale
(Built-in Mathematica Symbol) Scale[g, s] represents graphics primitives g scaled by a factor s. Scale[g, s, {x, y, ...}] scales with the point {x, y, ...} kept fixed. Scale[g, {s_x, s_y, ...}, ...] ...
Setting
(Built-in Mathematica Symbol) Setting[expr] replaces control objects such as sliders or popup menus in expr by their settings.
ShowSpecialCharacters is an option for Style and Cell that specifies whether to replace \[Name], \:nnnn, etc. by explicit special characters.