A parliamentarian is a meeting professional who can assist your organization in planning meetings, including your conventions. According to Robert's Rules of Order, Newly Revised  (12th edition) a parliamentarian is "a consultant...who advises the president and other officers, committees, and members on matters of parliamentary procedure."  (RONR, 47.46).   During a meeting, a parliamentarian who advises the presiding officer on issues that may arise during the meeting. Depending upon the needs of the organization, a parliamentarian may be asked to teach classes, respond to questions from members.