The Review Board was a permanent subcommittee of the Federation Council that was responsible for the admission of new worlds into the United Federation of Planets. As such, all the relevant diplomatic data along with first contact information were available to them. In addition, the Board was known to send its members on fact finding missions on the applicant world. Once a request was made for admission into the Federation, the Board sent a cultural attache along with a team to assist him in determining whether the planet along with its culture met with the requirements of entry.
Due to the importance of the role, the cultural attache was required to be a skilled individual along with being a highly experienced diplomat. Part of their duties involved a tour of the planet or planets of the culture in question as well as an extensive examination along with a review of he society's culture, economy, religion, science, government and its resources. A great emphasis was placed on attention to detail with the attache's team conducting a long review period of the applicant society. Once completed, the cultural attache returned to the Review Board and files their report to the subcommittee who usually provided a verdict within the following few weeks.
The verdict of the Board was rarely a surprise to the applicant culture as part of the cultural attache's duty was an explanation of the United Federation of Planets Constitution. A key aspect of the review was that the potential member society fully understood the principles highlighted within the Constitution. (Decipher RPG module: Player's Guide)