CWR records are divided into fields, each following a clear pattern, which consists on defining the following properties:
The field name is used only to help humans identifying the field, while the start index and size serve to acquire the data from the record line.
| Format | Code | Notes |
|---|---|---|
| Alphanumeric | A | ASCII characters in upper case. |
| Boolean | B | A single character. Can be ‘Y’, for yes, or ‘N’, for no. Meaning the Boolean values True and False. |
| Flag | F | The same as Boolean, but adding a third option: ‘U’ for unknown. This can’t be parsed into a Boolean value. |
| Date | D | Eight numeric characters, following the pattern YYYYMMDD. |
| Numeric | N | Usually an integer, sometimes a float value. In that case the field documentation indicates how many characters are for the decimal value. |
| Time | T | Six numeric characters, following the pattern HHMMSS. It is on military format (24 hours, and not two groups of 12). |
| List/Table Lookup | L | Only accepts values coming from a specific list or table. The table is indicated in the field description. |
Fields may be optional, or there may not be any data to put in them. In those cases, the empty columns must be filled as follows.
| Format | Code | When empty |
|---|---|---|
| Alphanumeric | A | Columns should be filled with the empty character. |
| Boolean | B | ? |
| Flag | F | Should be set as ‘unknown’ (‘U’). |
| Date | D | Columns should be set as 0. |
| Numeric | N | Columns should be set as 0. |
| Time | T | Columns should be set as 0. |
| List/Table Lookup | L | Columns should be filled with the empty character. |
Date and Time formats have additional constraints due to the patterns they follow.
Date follows the pattern YYYYMMDD, which has the following constraints:
Time follows the pattern HHMMSS, which has the following constraints: