Considerations
Truncation occurs when blank characters are removed from the end of records on the spool. If blank truncation is in effect, the result can be the same as if the input file contained variable-length records.
Blank truncation is a consideration at the time the input records are passed to the
print server. In the JES2 environment, blank truncation occurs unless the BLNKTRNC=NO parameter is specified. In the JES3 environment, blank truncation occurs unless the
TRUNC=NO parameter is specified as part of either the BUFFER or SYSOUT initialization statements. Blank truncation can affect conditional processing since
a field could disappear
by being truncated causing no WHEN/OTHERWISE clause to be executed.