It is the tracking # that the use to track your request. If you have not done so sign and date the document that you filled out on vetrecs. You should have been prompted to print this out. If you keep getting emails saying they have not received your signature, please sign and fax. If you lost the sheet you may have to fax them a letter but reference that tracking number.
Dear Mr. Adams,
Thank you for posting your request on History Hub!
We suggest contacting the National Personnel Center Records Center via their hotline at 314-801-0800. They will be able to identify the problem and suggest a solution. Please note that their peak hours are 10:00 am and 3:00 pm CST. Have the letter with your request number readily available.
We hope this information is helpful.