A formatted data file is one that has a structure file applied to it, and therefore is being displayed using one or more record layouts. An unformatted data file does not have a structure file applied, and therefore displays its records unformatted, as one continuous string, per record.
Editing the contents of a data file must be performed whilst the file is in exclusive mode, which places a lock on the file, so that others cannot also edit its contents. Once in edit mode, you have a number of tools to aid text manipulation, such as cut/copy/paste functions, duplicate entire records, and editing using hexadecimal values.
If you open a non-indexed file with the Use temporary file for editing option selected, which is available on the Open Data File and New Data File dialog boxes, edits are made in a temporary file before you commit them to the actual data file. This allows you to revert current changes, if required. If using a temporary file, [TEMP] is displayed in the file lock status indicator, beside EXCLUSIVE; you must use the Save all changes to file or Revert all changes to file to complete your edits.[5]