The main idea of the Cangjie (Cang Jie) system is that every character is built up from 24 basic signs. These signs - chosen a little bit metaphysically from the Five Elements, Yin and Yang theory and the realms of human nature, calligraphy and transformational stages - are laid upon the 24 keys of the computer board. The letters A to G are the key for signs corresponding to the natural world, like sun, moon, and the Five Elements metal, wood, water, fire, and earth (日,月,金,木,水,火,土); the letters H to N represent the world of calligraphy with seven different kinds of brush strokes (竹=丿,戈=丶,十,大=乂,中=丨,一,弓=亅); the letters O ro R represent the human world with man, heart, hand, mouth (人心手口); and the letters S to W and Y represent the transformational world like corpse=death, reunion, mountain=ascending, wife=creation, field=maturing, divination (尸廿山女田卜).
These main signs are representatives for similar shapes within a Chinese character. For example, the sign 手 "hand" (Q key) is representative for double crossed vertical lines, like the radical "hand" in the character 打, the upper and left part of the character 夫, the lower part of the character 奉, or the lower right part of the character 舜.
The following table gives an overview of the main signs (and their position on the keyboard), and the 111 secondary signs they represent.
By the way, Cangjie or Cang Jie 倉頡 was the mythological inventor of the Chinese script.

Q	W	E	R	T	Y	U	I	O	P
手	田	水	口	廿	卜	山	戈	人	心
A	S	D	F	G	H	J	K	L
日	尸	木	火	土	竹	十	大	中
Z	X	C	V	B	N	M
		金	女	月	弓	一

Q	手	hand 拿掌 hand radical 打 double crossed vertical line 奉邦責慧半 double crossed bow to the left 夫失替判 connected double crossed line 年舜	A	日	sun left 昭明 sun above 曰昆星 reclining sun 巴色象临
W	田	field 由苗 square frame 四國 square box with overlapping "content" 母毋	S	尸	corpse or house 尿尺屋 box open to the right 匹匡巨 box open to left, top or down 巨尹凸凹 strokes with edge and hook to the left 节司那局 comb-like characters like 耳取最怎作
E	水	water or similar 永泉求泰 three dots water 江 又 and similar 雙各	D	木	wood 樹李來 crossed lines, vertical part with hook 寸才于 crossed lines, horizontal part with long hook 也五皮力
R	口	mouth, small square box 呂足各	F	火	fire 炎灰狄 four dots fire and similar 蒸黑鳥 three dots on the top 光平米當 three spreading dots below 不示小
T	廿	twenty and similar boxes 革甘世某 grass radical 草華 double crossed horizontal lines 弄開并奔 廿 with long underdash 昔共其典 two dots on the top 業並前 and plate 皿 signs like 聯關 (lower right part)	G	土	earth 地圭王再 Sir 士壬志
Y	卜	oracle 外卡卞 vertical with rectangular horizontal stroke 上正非 horizontal stroke with dot on top 言文母丹 walking 通這 two free dots: 斗雨冬	H	竹	bamboo 筷答 short stroke to the left 白生壬么 double long strokes to the left 质爪反后
U	山	mountain 幽豐岩 box open to top 屈出函凸目 sprout 屮朔逆 long bend-edgy hook: 亂元電兆	J	十	ten; rectangularly crossed lines 支斗老 top roof 安宋家
I	戈	halberd 或成 one free dot 太主求甫 "tent" roof 廣席 厶 and similar 牟至玄	K	大	great 太奇夾爽 crossed curved lines 乂爽文殺狗 crossed lines with one horizontal 友左隋 sick 病
O	人	man 內坐肉仄 "standing" man 仁化 two spread lines on the top 全今 two oblique lines 每迄矢收段 two dots to the right 兆飛家 bow to the right: 入尺之爪八	L	中	middle 串革虫 vertical strokes 片川順友左隋 multiply crossed vertical strokes 康事建妻律 cloth radical 袖
P	心	heart 必忍 "standing" heart 情 four-dot heart 恭 comparing 比北皆印 seven 七化世也 a crossed bow to the right 代氏式我 wrap and similar 包象隊

Z and X are not used
C	金	metal 鍛釜 two short spreading strokes 分只益 two dots on the top 曾兌丫 spreading "feet" 兒匹四酉
V	女	wife 汝奴 crushed stroke of every kind 絲巡 square stroke to the right 繼亡叫 the lower part of "cloth" 衣表郎展 vertical stroke with hook to the right 氏民以
B	月	moon 朋有 large cover 且用岡同南雨 flat cover 骨受堂 lying moon or flesh 炙然祭察 head of animal 貌豹 claw 采愛舜
N	弓	bow 引雖第 bowed 乙鳳吃氣 horizontal stroke with hook to the left 买之今陳冰 parallel hooks to the left 色你吹 parallel hooks to the left with one long part 多久 vertical stroke with hook to the left 丁行利
M	一	one; horizontal stroke 三于天示 dot to the right 刁冷冰 dotless head: 压原石頁 working 工江左攻

How to use the Cangjie system?
A character can be separated into different signs (if it does not consist of the sign itself, like 木手心). But: forget about the radicals! The components or signs have nothing to do with the radicals.
The orderly sequence of these signs is

• from top to bottom, like JWJ for 車 (十田十) or GR for 吉 (士口),
• from left to right, like VE for 奴 (女又) or AB for 明 (日月),
• and from outside to inside, like TM for 甘 (廿一) or WD for 困 (囗木).

More complex characters are analyzed in the following way:

• The character 面 is composed from the signs 一囗卜卜丨 (MWYYL).
• The character 事 is composed (from top to bottom) of 十,中, a multiply crossed vertical line, and 亅 (JLLN).
• The character 輥 is composed of the parts 車 JWJ (十田十) and 昆 APP (日七七).

But how to elect the signs of complicated characters to shorten the key code to maximum five signs or keys? Complicated characters are analyzed according to their appearance if they have the shape of

• One single block (one-unit character like 面, max. 4 signs). If a one single block character has more than four signs, the 1st, 2nd, 3rd and last is chosen.
  • The key code of 面 should be MWYYL (一口卜卜丨), but the 4th sign is skipped, resulting in the key code MWYL.
  • The key code of 禺 is WLBI (田丨冂厶); further examples for one-unit characters are 來雨商求
  • 鼻 is no single block character although it is a radical: the components are 自田廾
• Two separable parts (two-unit character like 輓 - from 車免, max. 5 signs). The first unit counts with two signs, the 1st and the last; the second unit counts with three signs, the 1st, 2nd and last.
  • The key code of 輥 should be JWJ APP (十田十日七七). Instead, the left part is abbreviated as JJ (十十, 1st and last), and the three parts of the right part are used in full, resulting in the key code JJAPP.
  • The key code of 輓 should be JWJ NAHU (十田十,top zigzag,日丿乚). Instead, the left part is abbreviated with 1st and last sign, the right part is abbreviated as NAU (1st, 2nd and last).
  • The character 蟬 is compounded of the units 虫單 with the signs LMI RRWJ (中一丶口口田十), abbreviated to LI (1st and last) RRJ (1st, 2nd, and last).
  • Separable blocks on the top count as one unit if they have the appearance of a group: 想 and 惑 are a two-unit characters, 慧聯歐 are three-unit characters. This rule simply follows the "natural" composition of the character like one would analyze them according to the principle of radical and phonetic.
• Three separable parts (three-unit character like 窈 - from 穴幺力, max. 5 signs). The first unit counts with two signs, the 1st and the last; the second unit counts with 2 signs, the 1st and the last; the third unit counts with only one sign: the last sign.
  • The key code of 窈 should be JC VI KS (宀儿ㄥ厶ナ亅). The first part is taken full (1st and 2nd sign), the second part too, but from the third part, only the last or second sign is taken, resulting in the key code JC VI S.
  • The character 辦 should have the key code YTJ KS YTJ (dotted top,horizontal with two dots,十ナ亅,dotted top,horizontal with two dots,十). Instead, the first unit is abbreviated to YJ (1st and last sign), the second is taken full with only two signs, and the last unit is abbreviated with J (last sign), resulting in YJKSJ.
  • If the first and/or second unit consist of only one sign, the third unit is allowed to be composed of two signs (1st and last). Example: The character 嗨 is separated into the units 口,three dots water,每 with the corresponding keys R E OWMY, abbreviated to R E OY. In this case, the first and second unit consist of only one sign, leaving over two signs for the third unit.

The order of the parts is the same like the order of the signs. If a unit consists of only one sign, this one is taken. There are a few exceptions and rules:

• The first or preceeding sign must cover as much surface of the character as possible:
  • 夫 is double crossed line to left,stroke to right bottom (QO), not 土人 (GO).
• The character must be analyzed with as few signs as possible:
  • 王 is 一土 (MG), not 一十一 (MJM)
  • 共 is 廿八 (TC), not 廾一八 (TMC)
• Never break calligraphy strokes in two:
  • 力 is KS (crossed with one horizontal,stroke with edge and hook to the left), not KN (crossed with one horizontal,vertical stroke with hook to the left)
  • 之 is INO (丶,乛,乀), not BHO (亠,丿,乀)
• Signs never cross each other:
  • 申 is LWL (丨田丨), not LW (丨囗)
  • 者 is JKA (十乂日), not GHA (土丿日)
  • Exception are the signs 大木火七戈: 夷東束脊眷钱彧 and 巾典弗
• If a unit has the shape of a wrap, the outer strokes are taken as the last sign of this unit, neglecting calligraphy rules:
  • The left part of 耐 is abbreviated to 一冂, not 一丨
  • The upper part of 曹 is abbreviated to 廿囗, not 廿廾
  • Other examples are the characters 盈殆尊醒需
• There are also other exceptions for very complicated components or units:
  • 門 is AN (日丨), not ALAN
  • 鬼 is HI (厶丿), not HWH(U)I
  • Similar abbreviations are made for the characters 目(BU),隹(OG),虍(YP),气(ON),鬥(LN), the radical 阝 (LN), the phonetic part of 幾畿 (VI), and the top of 贏嬴 (亡口;YR).
• And there are exceptions for complicated characters; for these abbreviations, the letter X is used.
  • Difficult groups are abbreviated by the 1st sign and X: 肅(LX),與(HX Y C),臼(HX),興(HX B C),盥(HX B T),齊(YX),卍(NX; the Buddhist Swastika)
  • or abbreviated with the 1st sign, X, and last sign: 身(HXH),鹿(IXP),兼(TXC),慶(IXE),龜(NXU),黽(RXU),廌(IXF),淵(E LXL),姊(V LXH)
  • The groups 气羽 are seen as one unit - if they are in first position or the second of three units - and are abbreviated with their 1st and last sign, like 氣暣廖習. The same rule is valid for the following groups that are seen as one unit and are abbreviated by their respective 1st and last sign: 厭厥厤鴈辰雁(應)府麻.

Cangjie can be used for both traditional and simplified characters (in the list above you will find some simplified characters like 临节) and even for Cantonese vernacular characters (if these characters are included in a computer encoding system or the Hong Kong Supplementary Character Set Xianggang zengbu zifu ji 香港增補字符集). There exists also a simplified version of the Cangjie system called Easy Cangjie, making it possible to input any character by only two letters. Traditional Cangjie, for example, needs five letters to input the character 辦, YJKSJ, Easy Cangjie simply needs two letters, Y and J for the upper left sign (亠) and the lower right sign (十).