The struct that is included with the IDL for that account will include that field.
It would be nice to mark it as optional or padding so that code generators can treat it differently.
Existing code generators like solita wouldn't have to be updated at this point since they will just include that field with the deserialized account data (zero filled) and SDK clients just have to know not to use it.
However this could be made explicit, i.e. via a comment or special naming once these fields are specially marked.
In order to ensure accounts stay the same size even if more fields are added to the data struct, that data is padded.
Shank should allow this to be expressed via a padding field similar to this:
The struct that is included with the IDL for that account will include that field. It would be nice to mark it as optional or padding so that code generators can treat it differently. Existing code generators like solita wouldn't have to be updated at this point since they will just include that field with the deserialized account data (zero filled) and SDK clients just have to know not to use it. However this could be made explicit, i.e. via a comment or special naming once these fields are specially marked.