^start of string
?matches at most one character from the set below:
-the literal - (4510 / 558 / 2D16)
+the literal + (4310 / 538 / 2B16)
\d*a digit, repeated any number of times
.?optionally matches any character (except for line terminators)
\d*a digit, repeated any number of times
$end of string, or before its final line terminator
g modifier: global. Finds all matches instead of stopping after the first