Assessment procedure for deficient central statutory forms clarified, allowing extensions, limited information requisitions, and recovery action where appropriate. Assessments for tax periods where deadlines for submission of central statutory forms through DVAT 51 have expired should be framed; consider all forms filed within the statutory or extended period and admit post deadline forms only if an extension application was made on or before the due date (normally noted on Form DVAT 51). Assessing authorities may grant extensions on merits under the proviso to Rule 12(7), limit section 59 requisitions where complete forms exist, pass nil demand orders where information was sought but forms are not deficient, and pursue other deficiencies and recovery proceedings as prescribed by law.