Points are classified as channel, extra, or ashi points.
1. Channel Points
The points distributed along the course of the fourteen channels (twelve regular channels plus the ren and du mai) are called ‘points of the fourteen channels’, or ‘channel points’ for short. A channel point has a definite name, fixed location, and specific indication. The Yellow Emperor’s Inner Classic mentions 365 points, 160 of them actually named in this earliest classic. The Systematic Classic ofAcupuncture and Moxibustion (Zhēn Jiŭ Jiă Yĭ Jīng, 针灸甲乙经) records 349 points; the IllustratedClassic of Acupoints on the Bronze Figure (Tóng Rén Shū Xué Zhēn Jiŭ Tú Jīng, 铜人腧穴针灸图经) records 354; The Great Compendium of Acupuncture and Moxibustion (Zhēn Jiŭ Dà Chéng, 针灸大成) records 359; the Supplement to Important Formulas Worth a Thousand Gold Pieces (Qiān Jīn YìFāng, 千金翼方) records over 190 extra points. The Source of Acupuncture and Moxibustion (ZhēnJiŭ Féng Yuán, 针灸逢源), compiled in the late Qing dynasty in 1817A.D., records 361 points; this is the number still used today.
2. Extra Points
Points with definite locations that have not been recognized as belonging to the fourteen channels have specific names and indications and are called ‘extra points’. These were derived from ‘ashi points’, but extra points have relatively fixed indications, and most are used for specific disorders. For example, jĭng băi láo (EX-HN 15), is effective for scrofula, and sì fèng (EX-UE 10) is used for infantile malnutrition. Some extra points are not single points but a group: shí xuān (EX-UE 11), bāxié (EX-UE 9), bā fēng (EX-LE 10), and jiā jĭ (EX-B 2), for example.
3. Ashi Points
Ashi points are simply sensitive spots; they have neither definite names nor fixed locations. They are found by locating tender places or are points that reflect some quality pertinent to a disorder. Most ashi points are located near diseased areas, but some are distal to the affected site. The term ‘ashi point’ was first mentioned in the book, Important Formulas Worth a Thousand Gold Pieces for Emergency (Bèi Jí Qiān Jīn Yào Fāng, 备急千金要方), but the method of locating such points was mentioned much earlier in The Yellow Emperor’s Inner Classic and was called ‘determining points at tender spots’.
The name of a point usually has a specific meaning. Sun Si-miao (581-682A.D.) said in his book Important Formulas Worth a Thousand Gold Pieces for Emergency that ‘the names of points are not random but have profound meanings’. The meanings of point names were recorded in ancient literature. Ancient scholars assigned names based on a myriad of subjects ranging from astronomy, geography, daily life, natural objects, and anatomy to characteristics of point distribution, function, and indication. Point nomenclature is summarized below.
1. Nomenclature Based on Astronomy and Geography
Points named for the sun, moon, or stars: GB 24 (rì yuè) refers to the sun and the moon; RN 21 (xuán jī), DU 23 (shàng xīng), ST 23 (tài yĭ), and SP 3 (tài bái) are names of stars; ST 25 (tiānshū) refers to the pivot between the heaven and earth.
Points named for mountains, hills, or valleys: BL 57 (chéng shān) means supporting the mountain; LI 4 (hé gŭ) means the junction of valleys; PC 7 (dà líng) is a large mound; ST 34 (liángqiū) is a ridge in the hills; GB 40 (qiū xū) is a mound of ruins.
Points named for seas, rivers, streams, or ponds: SI 3 (hòu xī) means back stream; SJ 6 (zhīgōu), a small ditch; SJ 9 (sì dú), the four rivers; HT 3 (shào hăi), the lesser sea; LU 5 (chĭ zé), a marsh; LI 11 (qū chí), a crooked pond; LV 8 (qū quán), a crooked spring; LU 8 (jīng qú), a channel gutter; LU 9 (tài yuān), supreme abyss.
Points named for roads, paths, or passes: ST 30 (qì chōng) is the qi pathway; ST 28 (shuĭdào), water pathway; SJ 1 (guān chōng), a key pass; PC 6 (nèi guān), internal pass.
2. Nomenclature Based on the Activities of Human Beings and Objects
Points named for animals and plants: LU 10 (yú jì) means fish border; RN 15 (jiū wĕi), turtledove tail; ST 32 (fú tù), crouching rabbit; ST 35 (dú bí), calf nose; BL 2 (cuán zhú), gathered bamboo.
Points named after buildings or parts of buildings: SJ 10 (tiān jĭng) is a patio; RN 18 (yùtáng), jade palace; RN 14 (jù què), great palace gate; SI 13 (qū yuán), curved wall; ST 14 (kù fáng), storehouse; SP 13 (fŭ shè), a dwelling; SI 16 (tiān chuāng), an upper window; ST 4 (dì cāng), an earth granary; ST 21 (liáng mén), beam gate; RN 19 (zĭ gōng), purple palace; ST 44 (nèi tíng), internal courtyard; ST 13 (qì hù), qi door.
Points named after commonly used tools: BL 11 (dà zhù) is a large shuttle; SP 8 (dì jī), earth pivot; GB 38 (yáng fŭ), auxiliary tool; ST 12 (quē pén), basin; LI 17 (tiān dĭng), heavy cooking vessel; GB 39 (xuán zhōng), suspended bell.
Points named after human affairs: ST 9 (rén yíng) is a meeting of people; DU 20 (băi huì), a gathering of hundreds of people; ST 29 (guī lái), returning home; ST 36 (zú sān lĭ), a distance of three miles.
3. Nomenclature Based on Point Location and Function
Points named for their anatomical locations: SI 4 (wàn gŭ) is the wrist bone; GB 12 (wán gŭ), the mastoid process; DU 14 (dà zhuī), large vertebra; RN 2 (qū gŭ), pubic bone; BL 64 (jīng gŭ), the tuberosity of the 5th metatarsal bone; LI 16 (jù gŭ), big bone.
Points named for zang-fu organ functions: BL 44 (shén táng) is the palace of the spirit; BL 42 (pò hù), the door of the corporeal soul; BL 47 (hún mén), the door of the ethereal soul; BL 49 (yìshè), the house of reflection; BL 52 (zhì shì), the room of the will.
Points named for channels, collaterals, and yin-yang: SP 6 (sān yīn jiāo) is the intersection of the three yin channels; SJ 8 (sān yáng luò) connects the three yang channels; KI 19 (yīn dū) is a yin gathering place; BL 48 (yáng gāng) is an outline of yang; SP 9 (yīn líng quán) is a spring on the yin aspect of a hill; GB 34 (yáng líng quán) is a spring on the yang aspect of a hill.
Points named according to function: RN 24 (chéng jiāng) receives fluid; ST 1 (chéng qì) receives tears; GB 2 (tīng huì) is for hearing; LI 20 (yíng xiāng) welcomes fragrance; RN 6 (qì hăi) is the sea of qi; SP 10 (xuè hăi), the sea of blood; GB 37 (guāng míng) brightens vision; RN 9 (shuĭfēn) separates water to treat edema.