札

1. Origins, structure, and basic meaning

• Structure: 札 is read as ふだ in this entry and is a noun for a tag, placard, or sign bearing a name or caution.
• Basic usage: Use 札を掛ける for hanging one and 札が付いている for its attached state.

2. Common pitfalls and similar expressions

• Message and physical label
  • A name or 取扱注意 is the information written on the label; 札 is the object attached to the door or box.
• Reading and action
  • The reading here is ふだ, not さつ; 掛ける describes hanging, while 付いている describes being attached.