+While it appears possible with the template switch to update data sources
+asynchronously, B<RRDtool> implicitly assigns non-COMPUTE data sources missing
+from the template the I<*UNKNOWN*> value.
+
+Do not specify a value for a COMPUTE B<DST> in the B<update> function. If
+this is done accidently (and this can only be done using the template switch),
+B<RRDtool> will ignore the value specified for the COMPUTE B<DST>.
+