Thank you Chez311 and pmarc.
To add some more clarity, yes, it's for a plastic molded part.
Datum A is a collection of surfaces - all around of a shroud's internal wall.
Datum B is a single planar surface perpendicular to the wall, and No targets used (which makes it more ambiguous as the area of interest is same for the measurement and the datum). And of course CZ added to a planar surface is an overdo in this case as it is a single surface.
@Chez311; As you said, In your example is a definition that is becoming commonly used for molded parts as it can put a control on all the rest of the areas on part other than functionally important with a single annotation, and Functional requirements could be later defined as needed.
But this is mostly used with 3 Datum / 6 degrees locked.
Now the doubt from the query: Is there a change in the meaning when only Datum A in the FCF is used in that case, because with B in FCF or without it, the surface is meant to be a chebichev Best fit (correct me If I'm wrong)since no additional degree constraints other than A (&B) is mentioned/needed.