The Schedule FA page says the schedule applies to ITR-2, ITR-3, ITR-5, ITR-6, and ITR-7. The declaration note says the correct form is one other than ITR-1 and ITR-4, and that those two forms do not have Schedule FA, Schedule FSI, or Schedule TR. Schedule FA is the assets and the income from them. Schedule FSI is income accrued or earned outside India, and the tax relief on it. Schedule TR is the summary of tax relief claimed for tax paid or withheld outside India.
If a treaty benefit applies, the note says file form 44 online, in addition to Schedule TR. The treaty page is section 159. This page does not repeat the certificate rules.
The note says the disclosure goes in the return before the due date under section 263(1), 263(4), and 263(5). Subsection (4) is a return that was not filed in time under subsection (1). It may be filed within nine months from the end of the tax year, or before the assessment is completed, whichever is earlier. For tax year 2026-27 the note prints a belated return until 31 December 2027. Nine months after 31 March 2027 is 31 December 2027. On the belated line, the note and the section use that day.
Subsection (5) is a revised return, after a return under subsection (1) or (4), where the person finds an omission or a wrong statement. The window is the same nine months from the end of the tax year, or before the assessment is completed, whichever is earlier. The note's revision line is different. It says revise before the due date for revising the return, that is before 31 March 2028, and if the original return was ITR-1 or ITR-4, choose the correct form and fill Schedule FA, Schedule FSI, and Schedule TR. Nine months after 31 March 2027 is 31 December 2027. The note prints 31 March 2028. This page does not treat those as one date.
Which of ITR-2 and ITR-3 fits the rest of the income is on the ITR filing guide. The calendar-year reporting period, and the disclosure window to 31 December 2026, stay on the Schedule FA page.