The RECORDING MODE clause specifies the format of the logical records in the file.
General Formats for Format 1 (Record Sequential Files)
General Formats for Format 2 (Line Sequential Files)
General Formats for Format 3 (Relative and Indexed Files)
F and FIXED are synonyms.
V and VARIABLE are synonyms.
General Rules for All Formats (All Files)
Specifying RECORDING MODE IS F causes all the records in the file to be the same length.
General Rules for Format 1 (Record Sequential Files)
The "U" option is documentary only.
General Rules for Formats 1 and 3 (Record Sequential,Relative and Indexed Files)
When RECORDING MODE IS V is specified, the records in the file can be either fixed or variable in length. Each data record
includes a record length field. These fields are not part of the record description.
General Rules for Format 2 (Line SequentialFiles)
Line sequential files are neither truly fixed nor truly variable format files: the presence or absence of any RECORDING MODE,
RECORD CONTAINS or RECORD VARYING IN SIZE clause does not, therefore, impact their performance.