Fixed field or .CSV files are optimal.
Helpful tips:
Include delimiters to identify each individual record in the file: This is always helpful, even if you have only one document in your library. However, when multiple letter codes are being generated, the use of delimiters becomes crucial. It is especially helpful if lines in your text file do not represent individual records. Delimiters are the best means of counting the number of records in a file (which is a check point included in our Confirmation Report) and ensuring that each record is correctly mapped to a single document. If there is any chance that records in a file vary in length, using delimiters becomes very important in determining where to stop and start the records.
Use nonstandard characters such as the tilde (~) as delimiters: Depending on the data itself, it may be beneficial to use non-standard characters such as the tilde (~) as a delimiter. This helps avoid “delimiter collision”, that is, the delimiter character being interpreted as part of the data itself.
