効力

1. Origins, structure, and basic meaning

• Structure: 効力(こうりょく) means the force or validity that makes a rule or agreement effective.
• Basic usage: It is used for rules becoming effective or ceasing to apply.

2. Common pitfalls and similar expressions

• Gaining or losing effect
  • 効力を持った means became effective.
  • 効力を失った means lost its effect.
• をもって marks the reference point
  • 改正日をもって means as of the revision date, marking when the effect ended.