The T conversion code uses the source data as a record id to the named file and returns data from this record.
The format of the conversion code is
|file||is the file name. This may be prefixed by either DICT followed by a space or by an asterisk with no space to reference the dictionary part of the file. Where necessary to avoid ambiguity, the file name may be enclosed in quotes.|
|c||identifies the action to be taken if the requested record does not exist of the field to be extracted is null. This is a single letter:|
|V||Displays a warning message and returns a null value.|
|I||Like V for input conversion, C for output conversion|
|O ||Like C for input conversion, V for output conversion|
|v||specifies the value position to be extracted from the returned data. If omitted, all values are returned with value and subvalue marks replaced by spaces.|
|i||specifies the field position of the data to be returned when performing an input conversion.|
|o||specifies the field position of the data to be returned when performing an output conversion.|
This conversion code is closely related to the TRANS() function. Where possible, TRANS() should be used in preference to the T conversion code for best performance.