Every one — not just the PDF, but what it means for you, which section it touches, and whether it's still in force.
A CBDT clarification/instruction under Section 119 on how to apply the law. Binding on the Department; a beneficial one helps you. Doesn't change the law.
Published in the Official Gazette — notifies rules, forms, rates, the CII, exemptions, DTAAs. It has the force of law.