The Kanji Kentei is a Japanese 検定 (kentei, “examination”) and one of the most popular in a series of similar exams available to test-takers in Japan. Its full name is 日本漢字能力検定 (Nihon Kanji Nōryoku Kentei), but it is hypocoristically known as 漢検 (Kanken).
The test evaluates takers' ability to read and write kanji, as well as knowledge of the Japanese languge from the perspective of kanji, with the various levels testing yojijukugo, ateji and jukujikun, as well as radicals and general vocabulary.
It is available in 12 tiers of increasing difficulty, with 10 being the easiest and 1 being the hardest; there are also intermediate grades between 3 and 2, and between 2 and 1: pre-2 (準二級 (junnikyū)) and pre-1 (準一級 (jun'ikkyū).
The earlier tiers, from 10 to 2, follow the Japanese education system, wherein the Jōyō kanji are taught: passing level 2 requires knowledge of all 2,136 such kanji and vocabulary using them. From levels 10 to 5 inclusive, all the content directly corresponds to the kanji assigned to each grade level (the kyōiku kanji), and levels 4 to 2 inclusive subsume increasing amounts of the rest of the jōyō kanji, which are gradually taught during the rest of students' secondary educations. It is widely taken by students in these levels, and is often promoted or encouraged by schools.
The levels above level 2 no longer constrain themselves to the limits of the jōyō kanji, and therefore amass vastly more difficulty than their predecessors; passing either of pre-1 or 1 is expected to take considerable extracurricular study, even for literate natives. Although it has been heard of to pass pre-1 after only a year of dedicated study, passing level 1 is dramatically harder. Among all the kentei, Kanken is most similar in content to the Nihongo Kentei, itself also a Japanese proficiency test intended for natives; however, Kanken is decidedly vastly more difficult, due to the sheer volume of material that must be studied and memorized.
In light of the above, these pages (this page and its subpages) intend to provide resources and documentation on the exam and its content, especially with regard to level 1, in order to provide an open, English-language reference for this material.
As regards the content of this Wiktionary, it does not as yet cover the full range of vocabulary that Kanken requires, but with time, Wiktionary may grow to be a good Kanken resource. Nevertheless, at present (unless this notice should become outdated), it is likely (and at any rate advisory) that students will need to refer to Japanese-only sources for much of their studies, at least as regards level 1.