World Sailing uses a system of assigning symbols to courses (course signals) which consist of letters and numbers. The number always relates to the number of beats that a competitor is to sail to complete that course.
O - an outer loop trapezoid
M - a windward / leeward with a leeward finish with starboard mark roundings ( commonly used for match racing)
A - course with an offset mark at the windward end
R - course with a reaching finish at the leeward end
So an LRA2 course would be a windward / leeward course with an offset mark at the windward end and a reaching finish with two windward legs
Click on the relevant course name to show and download it's diagram.