launchd confusion

Does the following documentation indicate that one may not fork()/exec() in a launchd process? I'm certainly getting strange console messages when I do, but it's not clear yet if that's due to malformed code or if it's because of the way launchd treats children of children processes.

Citation: launchd documentation

Creating and running a launchd job

Whether you're migrating a job to launchd from some other system job launcher, or you're setting up a job for a new service, there are a few basic requirements for the job.

Jobs run from launchd should not duplicate launchd functionality; for instance, they should not use chroot(2). Furthermore, they should not do the things normally required of daemon processes, such as detaching from the terminal they are initially attached to. The only things that are strictly prohibited, however, are fork()/exit() combinations (including indirect methods, such as the daemon(3) library call). A server which attempts to run itself as a daemon in this way will seem to have finished running, potentially leading to launchd respawning it, or disabling the service. As launchd does not get stalled waiting for a child that hasn't yet exited, it's not necessary to try to prevent it.