All IBM® programming systems create tape labels with the same standard label formats. However, the actual contents of each label field may vary from system to system. To see which fields of each label are functional for the operating system, refer to Figure 1, Figure 1, Figure 1, Figure 1, Figure 1, and Figure 1. Check the processing of these functional fields against the actual contents of the labels you want to use. This comparison should indicate whether the volumes are compatible or what modifications must be made.

Special attention should be given to the data set identifier field of data set label 1 (HDR1, EOV1, EOF1). The data set name in the label created by another system may contain embedded blanks or special characters. This name is compared to the data set name that you specify in the DD statement; therefore, you must enclose the name in apostrophes on the DD statement that requests this data set. z/OS MVS JCL User's Guide lists the restrictions that apply to enclosing a data set name in apostrophes. The apostrophes do not appear in the data set identifier field.

To match the name in the label, you may have to modify the JFCB after the DD statement information is used to update the JFCB.

The operating system can obtain certain data set characteristics from the standard data set label 2 (HDR2/EOV2/EOF2). Some IBM programming systems do not use or create data set label 2. The absence of data set label 2 does not interfere with normal processing by the operating system when the label information is specified by some other means. The functional information in data set label 2 (record format, block length, record length, tape recording technique, and printer control characters) can be furnished to the operating system either in the DCB macro or the DD statement.

If the first block on the tape is 80 bytes long and begins with VOL1 in EBCDIC or if it is at least 80 bytes long and begins with VOL1 in ASCII, then the tape must meet the requirements described in IBM standard labels or ISO/ANSI labels.