- command is idempotent. Note that without this parameter, if you
- call the function twice with the same values it will only add one
- item to the substvars file.
+ command is idempotent. (However, we generally don't bother,
+ and rely on the user calling dh_prep.) Note that without this
+ parameter, if you call the function twice with the same values it
+ will only add one item to the substvars file.