Under the Indian Trusts Act, 1882, a trust in relation to movable property is valid if declared by an instrument in writing, signed by the author of the trust or the trustee, OR by transfer of the property to the trustee. Which type of instrument is referred to here?

Section 5 of the Indian Trusts Act, 1882 is the governing provision that prescribes the mode and formalities for the valid creation of a trust. It draws a clear distinction between trusts over immovable property and trusts over movable property. For a trust of movable property, Section 5 lays down two alternative modes of valid creation: 1.      By a non-testamentary instrument in writing, signed by the author of the trust or the trustee; OR 2.      By transferring ownership of the movable property to the trustee (e.g., by physical delivery, endorsement, or assignment, no registration is required). The key term here is "non-testamentary instrument", which refers to any legal document other than a Will. A non-testamentary instrument takes effect during the lifetime of the person executing it, as opposed to a testamentary instrument (Will), which takes effect only after the executor's death.