Example:

Name an initial contact letter and IDR file "6.01.L6031" and "6.01.F4564 IDR# (Date issued)" , and name your follow up letter and/or IDR "6.02.File Name" . If the taxpayer/representative provides a response to the letter or IDR, save their response and any attachments as "6.03.File Name" . If the taxpayer provides correspondence that is not tied to a specific IDR, then name the file with the next chronological number (e.g., "6.04.File Name" , "6.05.File Name" , etc.)