Many committers have a special area of responsibility. These roles are called hats [Losh, 2002]. These hats can be either project roles, such as public relations officer, or maintainer for a certain area of the code. Because this is a project where people give voluntarily of their spare time, people with assigned hats are not always available. They must therefore appoint a deputy that can perform the hat's role in his or her absence. The other option is to have the role held by a group.
Many of these hats are not formalised. Formalised hats have a charter stating the exact purpose of the hat along with its privileges and responsibilities. The writing of such charters is a new part of the project, and has thus yet to be completed for all hats. These hat descriptions are not such a formalisation, rather a summary of the role with links to the charter where available and contact addresses.
A Contributor contributes to the FreeBSD project either as a developer, as an author, by sending problem reports, or in other ways contributing to the progress of the project. A contributor has no special privileges in the FreeBSD project. [FreeBSD, 2002F]
A person who has the required privileges to add his code or documentation to the repository. A committer has made a commit within the past 12 months. [FreeBSD, 2000A] An active committer is a committer who has made an average of one commit per month during that time.
It is worth noting that there are no technical barriers to prevent someone, once having gained commit privileges to the main- or a sub-project, to make commits in parts of that project's source the committer did not specifically get permission to modify. However, when wanting to make modifications to parts a committer has not been involved in before, he/she should read the logs to see what has happened in this area before, and also read the MAINTAINER file to see if the maintainer of this part has any special requests on how changes in the code should be made
The core team is elected by the committers from the pool of committers and serves as the board of directors of the FreeBSD project. It promotes active contributors to committers, assigns people to well-defined hats, and is the final arbiter of decisions involving which way the project should be heading. As by July 1st, 2004, core consisted of 9 members. Elections are held every two years.
Maintainership means that that person is responsible for what is allowed to go into that area of the code and has the final say should disagreements over the code occur. This involves involves proactive work aimed at stimulating contributions and reactive work in reviewing commits.
With the FreeBSD source comes the MAINTAINERS file that contains a one-line summary of how each maintainer would like contributions to be made. Having this notice and contact information enables developers to focus on the development effort rather than being stuck in a slow correspondence should the maintainer be unavailable for some time.
If the maintainer is unavailable for an unreasonably long period of time, and other people do a significant amount of work, maintainership may be switched without the maintainer's approval. This is based on the stance that maintainership should be demonstrated, not declared.
Maintainership of a particular piece of code is a hat that is not held as a group.