An eptoken is an 8-byte field returned by CSVQUERY. Use of CSVQUERY followed by a call to the fast data access service is often useful when dealing with programs that are already loaded, especially if their source is unknown. Given an eptoken, fast data can locate and usually access the true source of a loaded program even if it has been replaced on DASD since it was loaded. Beginning with z/OS® V1R12, fast data access service supports eptokens associated with z/OS UNIX path names.