Patient Portal - Message customization instead of "No availability''

When you go to the portal to make an appointment with a doctor or IPS and there is no availability, it only registers ''No availability''.
It would be more than important to be able to customize this message:

For example: doctor on maternity leave, please communicate directly with his secretary...
For example: off for an indefinite period, please communicate directly with his secretary...
For example: full schedule, next availability posted on...