控え

1. Origins, structure, and basic meaning

• Structure: 控え, read ひかえ, refers to someone held in reserve or a record kept separately.
• Basic usage: It is used both for reserve players and for a retained copy of a submitted application.

2. Common pitfalls and similar expressions

• 控え and コピー
  • コピー emphasizes that something is a copy. For a document, 控え emphasizes its purpose as a record kept for later reference.