null.
.RE
.PP
-.PP
.B reverse (\fInumeric-expr1\fB, \fIdata-expr2\fB)\fR
.RS 0.25i
The two expressions are evaluated, and then the result of evaluating
specified width, in network byte order (most significant byte first).
If the numeric expression evaluates to the null value, the result is
also null.
-
+.PP
+.B pick-first-value (\fIdata-expr1\fR [ ... \fIexpr\fRn ] \fB)\fR
+.RS 0.25i
+The pick-first-value function takes any number of data expressions as
+its arguments. Each expression is evaluated, starting with the first
+in the list, until an expression is found that does not evaluate to a
+null value. That expression is returned, and none of the subsequent
+expressions are evaluated. If all expressions evaluate to a null
+value, the null value is returned.
+.RE
+.PP
+.B host-decl-name
+.RS 0.25i
+The host-decl-name function returns the name of the host declaration
+that matched the client whose request is currently being processed, if
+any. If no host declaration matched, the result is the null value.
+.RE
.SH NUMERIC EXPRESSIONS
Numeric expressions are expressions that evaluate to an integer. In
general, the maximum size of such an integer should not be assumed to
extract an integer of the specified size, the null value is returned.
.RE
.PP
+.B lease-time
+.PP
+.RS 0.25i
+The duration of the current lease - that is, the difference between
+the current time and the time that the lease expires.
+.RE
+.PP
.I number
.PP
.RS 0.25i