If the remap contains a filler item, the filler item can be reduced in size or eliminated altogether, and new data items and group items can be added in the space made available.

The size of the record must not change; thus, the filler item must be reduced in size or eliminated to produce the proper size area. Filler items are similar to alpha items. Their size is specified in 8‑bit bytes, they are aligned on byte boundaries, and they are initialized to all bits on. Regardless of the position of the filler item declaration, the filler in the record is located after all data items and group items, and before all control items.

Items added to a fixed-format record must be added at the end of the record. Items added to the fixed part of a variable-format record must be added at the end of the fixed part, and items added to the variable part must be added at the end of the variable part.

New items can be required and must not specify a null initial value. If new items are required, a reorganization also is required. If the new items are required and an initial value is not specified or the initial value is null, a data error occurs during the reorganization. All items added to existing records have the initial value of all bits on; this includes Boolean items and field items. All items in newly created records have normal initial values.

Since the filler item starts on an 8‑bit byte boundary, the first newly added item must start on a byte boundary also. If an unused 4‑bit digit precedes the filler, the first new item is not properly byte aligned. In this case, the error message “ITEM ADDED” or “ITEM MISMATCH” results. To avoid this problem, ensure that the first added item is byte aligned. For example, if one of the new items is an alpha item or group item, put it first. Otherwise, the first new item must be inserted in a dummy group item.

When the item is deleted from the remap, it can be converted to a virtual item. The virtual item fills the space formerly occupied by the item, prevents the remap record format from changing, and eliminates the need to recompile programs which invoke the remap. Remap items can only be converted to virtual items when the actual item is deleted from the data set or from global data.

The two reasons for deleting an item from a data set and converting it to a virtual item are as follows:

When an item is no longer needed, it can be eliminated from the data set and converted to a virtual item. This saves space on disk.

When an item value can be computed based upon the value of other items in the record, it can be transformed to a virtual item. This saves space on disk and eliminates duplication of the computation in every program needing the value.

Recompile the DMSUPPORT library.