Delete zone/gridpoints extra

Hello, I am trying to delete zone and gridpoints information stored in extra variables in order to get the file slighter but I do not find a Fish or FLAC command to achieve that, any help? Thank you in advance.

At the moment, it is not possible to delete the extra info stored in zones/gps. However, we are planning to add this functionality in the future. In the meantime, we recommend that you assign extra indices gradually and avoid using unnecessarily large indices. This is because once a large index (N) is used, memory will be reserved for all extra indices from 1 to N, even if some of them do not actually store variables

Thank you Chen, I think it can be a good command for the future. In the meanwhile, I will follow your recommendation. Regards.