Warrant of authorization: written, signed search warrants required where authorities have reason to believe documents or undisclosed assets will not be produced.
Search and seizure under the Income Tax Act permits specified senior officers to issue a written warrant of authorization when they have reason to believe that documents will not be produced, that summonsed material has been withheld, or that undisclosed income or property is possessed; the warrant must identify person and place, be signed and sealed, be produced at the start of the search, and blank or incomplete warrants are invalid. (AI Summary)

Assessment of other person's income under Sec.153C allows AO to assess or reassess income when seized material pertains to them.
Under Sec.153C, when material seized during a search in one person's premises belongs to another person, the AO must be satisfied that the items pertain to that other person, hand the material to the AO having jurisdiction over them, and that AO shall proceed to assess or reassess the other person's total income in the same manner as assessments in search cases. Recording of satisfaction is a jurisdictional prerequisite based on cogent material, and abatement, multiple search interactions and scope of additions follow the procedural rules applicable to search assessments. (AI Summary)