Keys and radicals The basic character components in Cangjie are called radicals () or letters (). There are 24 radicals but 26 keys; the 24 radicals (the
basic shapes ) are associated with roughly 76
auxiliary shapes (), which in many cases are either rotated or transposed versions of components of the basic shapes. For instance, the letter A () can represent either itself, the slightly wider , or a 90° rotation of itself. (For a more complete account of the 76-odd transpositions and rotations than the ones listed below, see the
article on Cangjie entry in Chinese Wikibooks.) The 24 keys are placed in four groups: • Philosophical Group – corresponds to the letters 'A' to 'G' and represents the sun, the moon, and the
five elements • Strokes Group – corresponds to the letters 'H' to 'N' and represents the brief and subtle strokes • Body-Related Group – corresponds to the letters 'O' to 'R' and represents various parts of the human
anatomy • Shapes Group – corresponds to the letters 'S' to 'Y' and represents complex and enclosed character forms The auxiliary shapes of each Cangjie radical have changed slightly across different versions of the Cangjie method. Thus, this is one reason that different versions of the Cangjie method are not completely compatible. Chu also provided alternate names for some letters according to their characteristics as a
mnemonics. They form a rhyme to help learners memorize the letters, each group being in a line:
Keyboard layout for Cangjie method, based on
United States keyboard layout. Note the non-standard use of Z as the collision key.
Basic rules There are several general decomposition rules () that define how to analyze a character to arrive at a Cangjie code, as follows: • Order of decomposition – left to right, top to bottom, and outside to inside. • Geometrically connected forms (
compounds) - identify
components and break up the character, i.e. 想→相+心. • First component (字首) – usually the upper-most or the left-most part according to rule (1) Order of decomposition, i.e. 相. • The body (字身) – except the first component, i.e. 心. • Number of codes – take at most 5 codes • For non-geometrically connected forms, take at most 4 codes. • For geometrically connected forms, take at most 5 codes, 2 from the first component and 3 from the body. • if the first component has more than 2 codes, take the first and the last. • If the body has more than 3 codes, consider breaking it up further. • If it can be broken up into second and third components, take the first code from the second component and the first and last codes from the third. • If it cannot be broken up further, take the first, second and last codes. The rules are subject to various principles: • Conciseness () – if multiple ways of decomposition are possible, the shorter decomposition is considered to be correct. • Completeness () – if multiple ways of decomposition with the same length of code are possible, the one that identifies a more complex form first is correct. • Reflection of the form of the radical () – the decomposition should reflect the shape of the radical, meaning (a) using the same code twice or more should be avoided if possible, and (b) the shape of the character should not be "cut" at a corner in the form. • Omission of codes () • Partial omission () – when the number of codes in a complete decomposition exceeds the permitted number of codes, the extra codes are ignored. • Omission in enclosed forms () – when part of the character to be decomposed and the form is an enclosed form, only the shape of the enclosure is decomposed; the enclosed forms are omitted.
Examples with Cangjie input method version 5 with Cangjie input method on an
Android device • • This character is geometrically connected, consisting of a single vertical structure, so we take the first, second, and last Cangjie codes from top to bottom. • The Cangjie code is thus (JWJ), corresponding to the basic shapes of the codes in this example. • • This character consists of geometrically unconnected parts arranged horizontally. For the initial decomposition, we treat it as two parts, and . • The first part, , is geometrically unconnected from top to bottom; we take the first (, auxiliary shape of Y) and last parts (, basic shape of R) and arrive at (YR). • The second part is again geometrically unconnected, arranged horizontally. The two parts are and . • For the first part of this second part, , we take the first and last codes. Both are slants and therefore H; the first and last codes are thus (HH). • For the second part of the original second part, , we take only the last part. Because this is geometrically unconnected and consists of two parts, the first part is the outer form while the second part is the dot in the middle. The dot is I, and therefore the last code is (I). • The Cangjie code is thus (YR) (HH) (I), or (YRHHI). • (simplified version of ) • This example is identical to the example just above, except that the first part is ; the first and last codes are (I) and (V). • Repeating the same steps as in the above example, we get (IV) (HH) (I), or (IVHHI).
Exceptions Some forms are always decomposed in the same way, whether the rules say they should be decomposed this way or not. The number of such exceptions is small: Some forms cannot be decomposed. They are represented by an X, which is the key on a Cangjie keyboard. ==Early development==