Processing codes describe database links and data manipulation rules in dictionaries. The D3 dictionary defines file layouts and data structures.
Processing codes are used by various D3 system processors, such as the Update processor, to transform the value of data. Processing codes are stored in attribute-defining and file-defining items in file dictionaries. The processing codes are found in:
| Attribute 4 | Structure |
| Attribute 7 | Output-Conversion |
| Attribute 8 | Correlative |
| Attribute 14 | Input-Conversion |
| Attribute 20-30 | Hotkey (see Update processor) |
Output-conversion codes manipulate the display or format of data. They are applied prior to output from the Update processor, the Access List processor, or a FlashBASIC call.
Correlative codes are used by all the system processors. Correlative codes for attributes are applied by the sort or select processor when building a list of item-IDs and by the Update processor and the List processor prior to calling the output-conversions. Correlative codes in file-defining items are called when the item is filed, especially from the Update processor. Some correlative codes, such as stamps, item-ID generation, and FlashBASIC subroutines, are only called from the Update processor.
More than one processing code can be specified in an attribute by separating the codes with value marks (CTRL+V in the Update processor).
Input-conversion codes are used by the Update processor to validate data as it is entered. These codes include:
Algebraic functions
Edit patterns
D3 assembly code executions
FlashBASIC calls
Range limitations
Required fields
Input-conversion codes define single or multiple file indexing. This allows cruising through both the current file (that is, the file where the item resides) and other linked files.