A data definition item (formerly known as an attribute definition item) defines a specified attribute, that is, the characteristics of the data in a specified attribute. It defines the format and the type of processing required to generate an English report of that data.
Any number of data definitions can be set up in a dictionary file. Each data definition is usually associated with an attribute in a data item by specifying the attribute mark count (AMC) in attribute 2 of the data definition item. The AMC number references to the position of the attribute in each data item of the associated data sections. Hence, an item with AMC = 3 defines the data in attribute 3 of the associated data items.
When English processes an attribute, it looks for a data definition item in the file dictionary. If it fails to find one, it goes to the next level up (the MD) to look for a predefined data definition. Predefined data definition items with item ids *A1, *A2, *A3 *A4 and so on, are supplied in each MD. These have AMC's of 1, 2, 3, 4, etc., respectively.
Note: Refer to the English Reference for a detailed discussion of a data definition item.
| Item-id | Attribute name – Used in an English sentence to reference the attribute. |
| 001 | D/CODE – Defines the item as a data definition. This can be one of the following: A marks the item as a data definition item that is used to format an attribute whenever it is referenced in an English statement either explicitly or implicitly. S marks the item, the same as the 'A' code, except that the default column heading is suppressed when attribute 3 of the data definition is blank. 'S' is obsolescent as a backslash in attribute 3 now gives a 'null' heading. X marks the item, the same as the 'A ' code, except when the attribute is part of an implied output specification (for example, LIST GUESTS), in which case, the attribute is skipped by the English processor. |
| 002 | A/AMC (Attribute/Attribute Mark Count) – Specifies the attribute number/line to which the data definition refers. Exceptions are: 0 = Item-id The AMC can be a null if attributes 7 and 8 have only function codes which reference attribute numbers directly. |
| 003 | Column heading text – Displayed in an English report as the column heading for the defined attribute (AMC). A multi-line heading can be specified by separating individual lines with value marks (X'FD'). If a heading is not specified, the column heading defaults to the item-id of the data definition item, unless an 'S' is shown in attribute 1 of the DDI. If a backslash (\) is shown, a 'null' heading is displayed provided attribute 1 of DDI is 'A'. |
| 004 - 006 | Not used and reserved. |
| 007 | V/CONV Conversion codes – used for processing values specified in an English sentence (input conversion), or following sort and selection processing before output (output conversion). Multiple conversion codes, separated by value marks, can be entered. |
| 008 | V/CORR Conversion codes – used for processing data before sort and select operations, and before attribute 7 conversions are processed ('pre-processing'). Multiple conversion codes, separated by value marks, can be entered. |
| 009 | V/TYP – A code that specifies the position of data in the defined attribute column of a English report. A code is mandatory and must be one of the following: I Indented text. Same as T, except that all lines after the first line are indented by one character space. L Left aligned. Wrap to left edge of column if length of text exceeds the column width (attribute 10). The data is broken at column width without respect to blank spaces. R Right aligned. Wrap to right edge of column if length of text exceeds the column width (attribute 10). T Text data. Left aligned, text folds back to left edge at a blank (space) character, where possible, so as not to split a word between lines. U Unlimited. Print entire attribute on one line, ignoring column boundaries. |
| 010 | V/MAX – Specifies maximum width of the attribute column displayed by English. A numeric (decimal) value is mandatory. If the width specified in attribute 10 is less than the column heading in attribute 3, English defaults to attribute 3. A number of different data definition items can specify different column widths for defining the output format of the same data. |
| 011 - 020 | Not used and reserved. |