Originally, Filipino systems did not have ranking systems. The skill level of a practitioner was apparent in contests. Modern Arnis has 4 pre-black ranks, and 9 black belt ranks. The four colored-belts are yellow, green, blue and brown. One may train with or without rank.
Filipino systems lean toward informality.
Many of the customs that are associated with martial arts training in the Western mind are actually Japanese customs, and therefore lacking in Filipino systems. Classes are relaxed, but directed toward acquiring skill rather than socialization. Arnis sets are primarily partner drills, so most of class time is spent drilling with different class members. WMMS has organized the drills into groups to make sets easier to remember and class time more efficient. Basic advance retreat triangle footwork.