The title Shou Zhi uses the characters for a letter, a term familiar across Japanese and Chinese writing, which is why the clip circulates with that short, searchable name. With no clear single source tied to it, the sound has spread mainly as a utility cue on soundboards, shared for letter scenes rather than for a famous line or performance. Its continued use comes from that simplicity, as editors can drop it into storytelling, roleplay and meme videos wherever a written message needs a clear audio marker.