Dear,
Its always suggestable to move the CODING MASK through transport request.Because you can see the same data in all the clients and helps every user and consultant to have consistency in the configuration data.
Not only coding mask any configuration change needs to be transported through request and test in test and quality system and then move to PRODUCTION system.This helps to replicate same scenario in all clients if you have same configuration data across all clients.
Regards,
Pardhu