An “emergency appointment” means that it’s technically a civil service job, but no one could be found to fill it. (Maybe the list of test-takers has expired, maybe they’re looking for a special skill set). Since it’s an emergency appointment, you can apply in a normal way (send application, do interview, etc.) without taking a civil service exam. Emergency appointments usually last for one year. If you got hired, during that year, you would take the Public Relations civil service exam. Then, at the end of the year, City Planning would open the job to people everyone who took that exam, so you would interview to become a “regular” for that same job (and compete against a handful of other folks who took the exam). Hypothetically, you might not get it (for example, if you didn’t score well enough on the test, or if someone did better than you on the interview), and then you would be out of a job. But since you will be interviewing for a job that you’ve literally been doing for a year, you’ll probably get it.