可 is one of the most commonly used Japanese kanji, and it also has a lot of special readings in addition to the standard onyomi and kunyomi readings.
ONYOMI 音読み
-べ.き -be.ki -べ.し -be.shi
KUNYOMI 訓読み
カ ka コク koku
Examples
この試験は辞書持ち込み可です。You can use a dictionary for this exam.学生に限り入場可。Admission to students only.数学は何とか可を取った。I somehow got a passing grade in mathematics.それは可でもなく不可でもなしというところだ。It is neither good nor bad.