-"I<min>B<:>I<max>". If a value if smaller than I<min> or bigger than I<max> a
-warning or critical is returned, otherwise okay is returned. I<min> (and the
-colon) may be omitted and are then assumed to be zero. If I<max> (but not the
-colon) is omitted I<max> is set to positive infinity. If either I<min> or
-I<max> if set to B<~> they are set to negative and positive infinity,
-respectively.
+"I<min>B<:>I<max>". If a value is smaller than I<min> or bigger than I<max>, a
+I<warning> or I<critical> status is returned, otherwise the status is
+I<success>.
+
+The tilde sign (B<~>) can be used to explicitly specify infinity. If B<~> is
+used as a I<min> value, negative infinity is used. In case of I<max>, it is
+interpreted as positive infinity.
+
+If the first character of the I<range> is the atE<nbsp>sign (B<@>), the meaning
+of the range will be inverted. I.E<nbsp>e. all values I<within> the range will
+yield a I<warning> or I<critical> status, while all values I<outside> the range
+will result in a I<success> status.
+
+I<min> (and the colon) may be omitted,
+I<min> is then assumed to be zero. If I<max> (but not the trailing colon) is
+omitted, I<max> is assumed to be positive infinity.
+
+=item B<-m>
+
+If this option is given, "Not a Number" (NaN) is treated as I<critical>. By
+default, the I<none> consolidation reports NaNs as I<warning>. Other
+consolidations simply ignore NaN values.