Of the internal martial styles, LiuHe BaBa is ' rare'. It is a high bred matrix of principles and forms from various sources and times; it can be and has been described partially correctly by many sources depending on the point of view and depth of knowledge/experience. [The addended listing below was written and translated by teacher John ChungLi, available to his students.]   

   It is most often simply described as:
(1) a 3-way union of exercises in series of taiji + xingyi + bagua.
(2) a 4-part-series with an extra-special-part:  part-1: taiji, part-2: xingyi, part-3: bagua, and a part-4: called 'water'-style.  These views are both correct and incorrect.
(3) as an exericse-series that 'blends' together  'taiji', 'xingyi', and 'bagua' forms and principles, into its own unique exercise 'water' style, yet visually remains similar to the other three.

  The LiuHe BaFa exercise consists of sixty-six named-form-postures, each consisting of several motions, collectively the exericse-series including over five hundred martial applications [simple calculating 66x the number of applications within each form would held:  66x5=330, 66x7=462, 66x8=528] In practice, however, there are shorter and longer exercise-series depending on the teaching and the students stamina.

(4) As this 66-form exercise is divided into two sections, again, there are interpretations of each divisions'  utility and intent:  usually it is observed that the 'first' section is a routine more of a 'taiji' and 'xingyi' nature and that the 'second' section is a routine more of a 'bagua' nature. Again, this viewpoint is partly correct and incorrect; both sections can be shown to contain taiji-xingyi-bagua and 'water' style methods and applications.

(5) As there is a division of two sections, it has also been said that the first sections' intent is to bring about a integration of the mind-body relation; while the second sections' intent is more of an esoteric center-channel opening exercise; this is from a taoist qigong-spirit viewpoint. [suggested by taoist Eva Wong]

  This idea is also mentioned by the International Taoist Tai Chi Society Founder, Moy Lin-shin: "Lok Hup Ba Fa (or Liu He Ba Fa) originated with the Taoist sage Chen Hsi-I of Hua mountain (Hua Shan), who lived during the late Tang dynasty, about the 9th century of the current era.  Chen Hsi-I was known for his methods of cultivating health and longevity.  One of these methods was a set of movements known as Lok Hup Ba Fa, the six harmonies and eight methods of mind and intention. Recognized as the internal art par excellence the moves of Lok Hup are designed to stimulate and massage the internal organs and exercise the spine. The Lok Hup form consists of 66 movements that are noteworthy for their graceful, spiral turning. The movements may be regarded as an 'intensifier' of the turning and stretching effects that are already evident through the practice of Taoist Tai Chi. Movement originating from the spine forms the essence of Lok Hup and this art is most beneficial to students who have already developed some degree of spinal articulation through practice in Taoist Tai Chi."

(6) Another way to understand the 'what' and 'how' of this exercise comes from its'  names : 'water style' all of the movements can and in principle should be performed as  'floating clouds', 'flowing water', or as a 'swimming dragon'. Sometimes it is soft-slow and calm, at other times quick and surging.   [Today, one must always ask the question, is the current exericise derived from and continuous with 'water' qigong principles; or does it only contain a reminent of these original 'water' style-principles; or is it a hopeful recreation of them in name only?]  There currently exit three 'teaching' names for this exercise

LiuHeBaFa-Sanpan Shiershi: the principles of 'harmony' by 'methods' is achieved at 3-standing levels and by emmulating  form-principles of the 12-animals, shiershi [advancing, retreating, , which develop mobility skills for moving with a situation or partner.] {this is the line of teaching from Liu Yaoxing}

HuaYo-LiuHe-XinYi-BaFa: the high-standards [like Mt.Hua in Shenxi] guide to achieving 'harmony' by 'methods' [6 as 1 together and 8 method-principles], but the central guiding idea, is xinyi, the heart-center-intent or intention. {this is the line of teaching from the Chen YY. to Choi WaiLun traditional school} This title is also given as HuaYo-XinYi-LHBF, which can be read as famous Mt.HuaShan's 'intuitve' and the 6x8-unity-by-harmony text-principles.

HuaYo [HwaYue] taichi: Also, taking the most basic forms from LHBF and executing them to the soft, centralized principles of taichi-, this exercise has also been named ; this was a more modern naming by John ChungLi, however, Mr.Li was strongly influenced by teacher friends: TT.Liang while in Boston, and by Han XingYuan while in Hongkong; a touch of ChenManChing-syle with YiQuan; in itself a novel update and a simplification.

(7) A pragmatic historical/principle view would be that its' foundation utilizes both stepping, stance, and the axial-torque-power of LiuHe-XingYi-Quan, and that it adapts the the yin-yang turning-stepping and evading patterns of MiTsung-BaGua and Aikido, and that the resilient-absorbing/neutralizing principles and slowed-pace of practice characteristic of taiji carry throughout the exercise. This view is correct superficially and is also the official assessment of a noted martial-arts historian. {there  exists also personal documents from the survivors of Wu YuHui's family which counter-attest that the exercise does predate Msr.Wu.}

(8) A pragmatic observation is that the exercise encompasses the water-flowing principles [which can be shown  to have an ancient lineage] passed from the three immediate teachers of Wu Yi-Hui were bonefide in principle, but that the actual forms taught by Wu in Nanking show form and principle influence from the exercise known as Lu Hung's eight-strategies [which was also taught seperately] and some martial patterns drawn from other teachers of the Nanking Martial academy. [It can be easily shown that the complete system is also dividable into four (4) parts: a start=finish, a flowing-series which is best in principles, a martial-series mostly within the second half which is almost identical with the Eight-Strategies series (and is thus not a qi-gong like as the flow-series), and a standing and weight-shifting aspect that is partly like Yi-quan and partly like the 'universal' tai chi standing of Kuo Lien Ying, one-legged.]

Also, for current 'styles' of the exercise, there is further influence entering from the yi-quan standing exercises.  Neither of these degrades the LHBF, but both impede the flow character of 'water' style.