-More notes on the forms-
Disclaimer: The IWTA is a very large organization, more than large enough for discrepancies or differences of opinion to occur. You might especially find this to be the case if you train in the United States. However, since Wing Tsun is an art/science fueled by principles, it might be better to always speak in terms of percentages. Whatever the case may be, differing emphases and stylistic flares within the IWTA should only ever be a benifit to the organization. The principles remain unchanged.
The forms of Wing Tsun are somewhere between concise dictionaries and raw poetry. It is their very conciseness which makes them poetic. Rarely is a section of a Wing Tsun form a blunt fighting application, and if it is, that is never all it is. Wing Tsun forms are methods for achieving perfection of posture, stance and motion, and in this way they are like dictionaries. However, they can be analysed on deeper and deeper levels; they're bottomless. And in this sense, they are like poetry. This is not shadow-boxing.
An example: at the beginning of the first three forms, beginning with the feet together, the stylist turns her feet outwards from the heel, then pivots from the balls of her feet to achieve the IRAS (Internally Rotated Adduction Stance). On the top level, this motion is understood to be a simple way of achieving correct distance between the feet and proper adduction. However, on another level of interpretation, these two, simple rotating motions are the kernel for all Wing Tsun footwork.
Like poetry, repetition in Wing Tsun forms has a symbolic purpose. It creates a heirarchy of emphasis and divides the form into sections. In Wing Tsun forms, the transitions between postures are as least at important as the postures themselves. This is because Wing Tsun is a martial art of transition and change, cthonically liquid when properly learnt. Lao-tzu would weep.
The first form of Wing Tsun is often called the most important form of all. It contains core ideas, and is about equally divided between offense and defense. The third section of Siu Nim Tao has Chi Kung applications, and is the most health-beneficial. It is also the most esoteric and important. In comparison to the rest of the form, this section is to be done very slowly, and it is the only form section in all of Wing Tsun Kuen (that I am aware of) to receive a descriptor: "Praying Thrice to the Buddha." It involves a repeated transition from wu sao to man sao, the two positions that make up the hand placement of the wing tsun stance.
The second form, Chum Kiu (my form), is primarily a defensive form, although it introduces three kicks to the stylist's repertoire. The emphasis on defense is obvious when one considers the nature and purpose of such things as footwork and turning. In theoretical purely offensive scenarios (where no defense is necessary), no footwork is needed but the forward step. Bong Sao (the "signature move" of Wing Tsun) is emphasized, as is Fuk Sao. This is also the first appearance of close-range techniques such as the Lan Sao (WT elbow) and uppercut.
The third form, Bui Tze, is the primary offensive form of Wing Tsun. It contains fewer defensive techniques, but has some interesting methods for recapturing the center when one is in a perilous position. I can't comment any more than this, as even the practice of a form (and I'm not practicing this one yet) hardly guarantees comprehension, and there are infinite depths of comprehension to be attained . . .
The fourth form is a true mystery, but it seems to have an emphasis on coordination and cooperation of all levels of the body, as well various defensive and offensive shortcuts. The wooden dummy is not meant to strengthen the hands or arms; it is not a makiwara (padded rectangular board, mounted on a wall). Get a punching bag for that. The form should be done softly, and you'll know you're at a good school if it takes you roughly ten years to even begin this form.
The scope and quantity of the Wing Tsun curriculum is truly mind-boggling, and all of it can be seen as emergent properties and extrapolations of a few simple principles that are, ever and always, the true goal.
A final note: It has been suggested that each of the Wing Tsun forms represents an entirely different martial art. Any WT student can see there is some logic in this. Each form/art has its own core principles (which are extrapolations of the main principles), and a gamut of techniques that spring from them. Each is lightyears better than the last, but the catch is that they must be learnt sequentially . . .
--WT 5th student level, "Vikingist"