Interface FormatType

Remarks

It earns no entry of its own in curated chrome — the Save As menu, which is a short list of the formats most people want — while staying available everywhere the COMPLETE set is offered: the native picker's "save as type" dropdown, a --format argument, and IWorkbookIO.getWriteFormats itself. Nothing about reading or writing it is special-cased; only its prominence is.

This is a demotion, not a hiding: a format nobody may write does not belong in the registry at all. Use it where a menu entry would cost more attention than it earns — 'SheetXL Workbook (JSON)' next to 'SheetXL Workbook', whose difference (pretty-printed and uncompressed) matters to a developer and to no one else.

Remarks

This is a file-type NOUN PHRASE — '<Family> <DocumentKind>', plus an optional '(Variant)' — not a brand and not an adjective: 'Excel Workbook', 'SheetXL Workbook', 'SheetXL Workbook (JSON)', 'Comma Separated Values'. It goes verbatim into the native file picker's type list (the browser appends (*.ext) itself), so a bare brand ('SheetXL') reads as a vendor rather than a file type, and a bare adjective ('Comma Delimited') never says delimited what.

A variant belongs in PARENTHESES when it is a noun ('(JSON)'), and before the document kind only when it is a true adjective ('Excel Binary Workbook') — 'SheetXL JSON Workbook' stacks three nouns with no grammatical joint. Excel ships the parenthesized-and-then-extension form itself: 'CSV (Comma delimited) (*.csv)'.

It is also substituted into sentences such as "Save as {description}", which is the other reason it must stand alone as a noun.

Remarks

Must be unique across all format types.