49 C.F.R. § 845.30 – Board products.

(a) Reports of investigations.
1. (1) The Board will adopt a report on the investigation. The report will set forth the relevant facts, conditions, and circumstances relating to the accident or incident and the probable cause thereof, along with any appropriate safety recommendations and/or safety alerts formulated on the basis of the investigation. The scope and format of the report will be determined in accordance with Board procedures.
2. (2) The probable cause and facts, conditions, and circumstances of other accidents or incidents will be reported in a manner and form prescribed by the Board. The NTSB allows the appropriate office director, under his or her delegated authority as described in § 800.25 of this chapter, to issue a “brief,” which includes the probable cause and relevant facts, conditions, and circumstances concerning the accident or incident. Such briefs do not include recommendations. In particular circumstances, the Board in its discretion may choose to approve a brief.
(b) Studies and reports—(1) NTSB studies and reports. The NTSB may issue reports describing investigations of more than one accident or incident that share commonalities. Such reports are similar to accident or incident investigation reports, as described in paragraph (a)(1) of this section. Such reports often include safety recommendations and/or safety alerts, which the Board adopts.
(2) Safety studies and reports. The NTSB issues safety studies and reports, which usually examine safety concerns that require the investigation of a number of related accidents or incidents to determine the extent and severity of the safety issues. Such studies and reports often include safety recommendations and/or safety alerts, which the Board adopts.
(c) Safety recommendations. The Board may adopt and issue safety recommendations, either as part of a Board report or as a stand-alone Board product.