Various terminology crops up repeatedly when documenting KanjiVG, some of it quite specialised. This page gathers brief definitions of important terms so that repetition of explanation can be avoided.
A block of Unicode from U+31C0 to U+31E3 containing the shapes of individual kanji strokes. The names of the strokes, such as D or HZ, are the initials of Chinese descriptive names. See Stroke types in KanjiVG for how they are used by KanjiVG. See the Unicode documentation for more information about these.
A block of Unicode containing kanji. The basic block goes from U+4E00 to U+9FFF, but it was extended with CJK Unified Ideographs Extension A from U+3400 to U+4DBF, and other extensions.
Since the exact block of Unicode that a kanji belongs to is not vitally important to KanjiVG, in this documentation we refer to all of these blocks as the "CJK Unified Ideographs". However, we do distinguish these from the Kangxi Radicals block or the CJK Strokes block.
Generic groupings of strokes of kanji into meaningful parts are referred to as "elements" in this documentation. The word radical is reserved to mean the identifier of the kanji under a classification system such as the Kangxi radical system.
Part of the original effort of Unicode to fit as many characters as possible into sixteen bits by using the same code point for characters considered to be identical. These characters are often graphically different, thus the Japanese-style KanjiVG vector graphics for various Unicode code points are not appropriate for Chinese usage.
人名漢字 An extension of the Joyo Kanji for people's names. See variants.
第1・第2水準漢字 Two sets of kanji which were used as the basis for the coverage of KanjiVG. See Coverage in KanjiVG files. All of the 2,000 Joyo Kanji, and most of the Jinmei Kanji are in level one, and a further 3,000 or so characters are in level two, making around 6,000 kanji.
This is the kanji part of the JIS X 0208 standard. These sets were the standard sets of kanji available on Japanese-language computing platforms before the advent of Unicode.
There are further levels three and four, but KanjiVG does not cover them.
The schoolbook fonts are based on a style of Japanese writing known as kaisho (楷書). This is a non-cursive form of handwriting where each stroke is written separately.
A block of Unicode from U+2F00 to U+2FD5 containing the canonical form of the 214 Kangxi radicals. Characters from this block are not used by KanjiVG.
For brevity's sake, the KanjiVG documentation uses the word kanji to indicate sinographs, Chinese characters, hanzi, and so forth. We sometimes use the term "Chinese characters" when referring specifically to characters used in China rather than in Japan.
The altered radicals used in the Nelson kanji dictionary. Nelson used a more systematic approach to recategorise kanji into radicals, resulting in different values than the Kangxi radical system. This was also copied into the Kanjidic online kanji dictionary.
In the KanjiVG documentation and files, "radical" is used as a translation of the Japanese term 部首, which essentially means the Kangxi radical of the kanji, a group of strokes which can be used to categorise the letter.
Some people also refer to the various other component parts of a kanji as "radicals", but KanjiVG reserves the word radical for a single identifier under a classification scheme, and uses the word "element" for the component parts of a kanji other than the radicals.
Japanese "schoolbook fonts" (教科書体) are fonts designed for Japanese children's textbooks. These fonts are made to resemble high-quality Japanese handwriting in the style known as kaisho.
Stroke order (筆順) is the order in which strokes of a kanji should be written. This becomes important in the case of cursive forms of Japanese handwriting, where the way in which the strokes are joined up depends upon the order in which they are written.
Radicals may have more than one visual form. For example, Kangxi radical 61, "water", may take a non-variant form 水, or it may take a variant form 氵.
Vector graphics is a type of computer graphic where the image is defined mathematically as a collection of graphical objects like curves and lines, rather than as a collection of pixel values, like the PNG or JPEG formats. Vector graphics have the advantage over pixel graphics that they can be scaled to any size without becoming blocky, and that the file size of vector graphics is often much smaller than an equivalent pixel format. They have the disadvantage that they can be difficult to create and edit, and they are not useful for storing some kinds of images, for example, photographic images.