An italic page number such as 123 indicates a definition. A light page number such as 456 indicates a brief mention. Page numbers followed by the letter t refer to tables. Only variables that must always appear with a leading dollar sign are indexed with a leading dollar sign. Other variables are indexed without a leading dollar sign.
^ in regular expressions 1014
^ quick substitution character 334
, (comma) operator 497
:– substitutes default values for a variable 473
:? sends to standard error an error message for a variable 474
:= assigns default values for a variable 473