Preservation of DVAT-43: contractors may file a photocopy with returns while retaining originals for inspection. The circular permits a contractor who received one copy of the DVAT-43 certificate from the contractee to file a photocopy of DVAT-43 with the DVAT-16 or DVAT-17 return, while preserving the original certificate for seven years and producing it to the Assessing Authority on demand.