NumberSigns

NumberSigns
is an option for NumberForm and related functions which gives strings to use as signs for negative and positive numbers.

NumberSigns->{"sneg", "spos"} specifies that "sneg" should be given as the sign for negative numbers, and "spos" for positive numbers.

NumberSigns->{{"snleft", "snright"}, {"spleft", "spright"}} specifies strings to put both on the left and right of numbers to specify their signs. »

Positive and negative numbers with default number signs:

Out[1]//NumberForm=

Add explicit positive signs:

Out[1]//NumberForm=

Parentheses are used for negative values in AccountingForm:

Out[1]//AccountingForm=