may override any parameter set in global sections.
.SH "JOB PARAMETERS"
.SS Types
-Some parameters may take arguments of a specific type. The types used are:
+Some parameters may take arguments of a specific type.
+Anywhere a numeric value is required, an arithmetic expression may be used,
+provided it is surrounded by parentheses.
+Supported operators are
+addition, subtraction, multiplication and division.
+For time values in expressions
+units are microseconds by default. This is different than for time
+values not in expressions (not enclosed in parentheses).
+The types used are:
.TP
.I str
String: a sequence of alphanumeric characters.