/* file system independent - file search parameters */
 
struct fsfsi {
        unsigned short  fsi_hVPB;       /* volume info. */
};
 
/* file system dependent - file search parameters */
 
struct fsfsd {
        char            fsd_work[24];   /* work area */
};

Existing file systems that conform to the Standard Application Program Interface (Standard API) described in this section, may not necessarily support all the described information kept on a file basis. When this is the case, file system drivers are required to return to the application a null (zero) value for the unsupported parameter (when the unsupported data are a subset of the data returned by the API) or to return a ERROR_NOT_SUPPORTED error (when all of the data returned by the API is unsupported).