This document discusses phono-semantic compound characters in Chinese. It explains that phono-semantic characters, also called pictophonetic characters, have two parts - a semantic part indicating meaning and a phonetic part indicating pronunciation. Around 90% of Chinese characters are phono-semantic characters. Examples are provided to illustrate how the semantic and phonetic parts are combined to form a character and indicate its meaning and pronunciation. The document notes that while the phonetic part provides a hint to pronunciation, the pronunciation of the full character may have changed over time.