other: RARELY USED. Any page or set of pages that does not clearly match any known form, schedule, or document type and is not supplementary documentation for the return. This includes ONLY cover pages, preparer transmittal letters, informational notices, redaction pages, or truly unrecognizable content. Blank pages should not be classified as 'other' — they should be grouped with the subdocument immediately preceding them. IMPORTANT: Before using 'other', verify the page is not: (1) a government-issued form (use 'misc_form' instead — if the page has a form number like 'Form XXXX' in the header, it is misc_form), (2) a supporting statement, worksheet, schedule detail, or software-generated page (use 'supplement' instead). The 'other' type should almost never be used in typical tax returns. The type field must always be exactly "other" with no additional text or numbers.