Mathematica includes a variety of non-printing characters, some used to fine-tune layout, and others used to define precise syntactic interpretations while maintaining the traditional look of various mathematical notations.
\[NegativeThinSpace] — "negative space" to bring objects closer together
\[LetterSpace] — an almost-invisible space treated as a letter, e.g. in a symbol name
\[NonBreakingSpace] — insert a space, but do not allow it to be at a line break
\[NoBreak] — ensure that no line break occurs at this point
\[IndentingNewLine] — insert a new line, with indentation on the next line
\[DiscretionaryHyphen] — hyphen to include only at a line break
\[AlignmentMarker] — represent a position that should be aligned in a grid
Invisible
Mathematica Syntax
\[InvisibleSpace] — invisible character treated like a space in
Mathematica syntax
\[InvisibleComma] — invisible character treated like a comma
\[InvisibleApplication] — invisible character making
f x behave like
f[x]
\[ImplicitPlus] — invisible character representing addition (e.g. in compound fractions)
