What is the travel rule in BitFlyer?

Could you please explain what the travel rule entails within the context of BitFlyer, and how it affects users engaging in cryptocurrency transactions on the platform? Is this a regulatory requirement or an internal policy implemented by BitFlyer to ensure compliance and security? How does it specifically impact the transfer of funds or digital assets between users on the platform? Additionally, are there any specific steps or procedures that users need to follow to comply with the travel rule when using BitFlyer?