DBFieldDef :: CanReference - Can field definition reference another one
When defining a field definition reference (reference variables or parameters), field definitions must be compatible. This function checks, whether the field definition passed can reference the current field definition.
Return value:  Return value ( logical  )
The function returns YES when the question was answered positively. Otherwise it returns NO.
Implementation details
logical 
DBFieldDef  :: CanReference ( DBFieldDef *fielddef )
- fielddef
 - Internal field definition
This is a pointer to an internal field definition (DBFieldDef or fmcb), which may describe attributes as well as references (collections). 

