| ### Bridge styles and attributes

- Wrapper (separate step) vs. Filter (interface)
- Forward (YY to CCYY) vs. Reverse (CCYY to YY)
- On-line vs. Batch
- Read-only vs. Update
- Full vs. Subset Extraction (selectively bridge records - a dual purpose bridge)

#### Filter-style bridge

These are utilities (possibly a jobstep) that act as filters between legacy format data and century format data. They act on a file or database level, not on a record-by-record basis.

| Forward Bridge (from legacy format to century format. (May include record selection in addition to format conversion) Backward Bridge (from century format to legacy format)

#### Wrapper-style bridges

These are subroutines, called on demand: on an as-needed, record-by-record basis. Replace your I/O statements with calls to the bridges.

Tip: Turn the existing I/O statement into a comment and mark it with some unique tag to make it easy to burn the bridge when the time comes.

| Forward bridge (from Legacy format to century format) Backward bridge (from century format to legacy format)

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