Default false. When true, a label that a select or multiselect column does not have yet is added to that column as a new option, and the cell is written with it; the response then lists the options this call created in created_options. A label within one or two letters (or only case/spacing, or two adjacent letters swapped) of an existing option is still refused with did_you_mean — a near-duplicate option is never created by a row write. An existing option shorter than four characters counts only an exact match regardless of case or a swap (Bgu next to Bug), so P2 next to P1 is created. When two options are equally near, did_you_mean is null and the error names them all. Labels whose numbers differ (Sprint 12 / Sprint 13) are not near-misses. Priority and other system-owned option lists never accept new options. In a multiselect labels are separated by commas, so a comma inside a new label is escaped as \, (Lviv\, Ukraine is one label Lviv, Ukraine) and a backslash as \\; a select reads the same escapes. An empty label is refused. A new label is at most 200 characters and may not contain control characters (line breaks, tabs), and one call adds at most 50 new options; an operation past either limit is refused as invalid. The same new label in several cells of one call is created once; a later spelling of it that differs only in case, spacing or a typo is refused with did_you_mean naming the first. Options are created before the rows that use them; this is not a transaction, so if creating one fails, the operation that needed it is failed, later operations are skipped, and options already created stay.