* {{Parameter|fileNumber%}} is the file number of the file to lock.
* In the first syntax, the entire file is locked.
* In the second syntax, {{Parameter|record&}} is the record number of the file to lock.
* In the third syntax, the records or bytes in the range [{{Parameter|firstRecord&}},{{Parameter|lastRecord&}}] are locked. If {{Parameter|firstRecord&}} is omitted, it is assumed to be one (the first record or byte).
* For files opened in [[BINARY]] mode, each record corresponds to a single byte.