OptionaladditionsValues the author typed, as text, one entry per item. Excel's typed list (Yes,No).
OptionalblankOOXML's filters/@blank, as a file carries it. Prefer the condition's includeBlanks,
which is the blank policy under every host: a reader sets both, and a filter call reads a
top-level blank as includeBlanks.
OptionalbyMatch string items against the text a cell SHOWS rather than the value it holds.
The identity is the value: items: [1] keeps every cell holding 1 however it is
formatted, and items: ['1'] keeps the cells holding the text 1. Under byDisplay a
string item is instead the displayed text, which is what a spreadsheet's filter list
holds: '1.50' keeps a cell holding 1.5 under 0.00, and '$1' one under $0. A typed
item is matched by value in both modes.
byDisplay is a filter's option, the one the column dropdown sets. A conditional format
or a data validation has no displayed text to read, so the flag is inert there. Under a
filter it also widens what is blank: a string of only spaces shows as nothing and is
settled as a blank cell, and a whitespace-only item means includeBlanks. A port of
Office Scripts' applyValuesFilter or Apps Script's setVisibleValues passes strings
and sets it.
OptionalcalendarCalendar type for date group items.
OptionaldateA snapshot's date groups: a year, a month of a year, a day, down to the second. A date inside any group matches.
OptionalitemsA snapshot's members: the values that match, as they were when the condition was authored.
OptionalsourceA live base: a formula whose result is the list, as formula text without a leading =
($A$1:$A$5, Sheet2!$A$1:$A$9, MyList, OFFSET(...), INDIRECT($E1)).
Evaluated for each cell, so a relative reference gives each cell its own list, and it follows inserts and deletes as any formula does. A resolved condition holds it as an ICalculation.IFormula.
OptionalsubtractionsMembers taken out of the set. A value that matches one fails, whatever part it came from.
What narrows a live base, where a member cannot be removed from the formula. A snapshot needs none: its unchecked members are simply not in items.
The set an BuiltInOperatorNames.InSet condition tests membership of.
Remarks
A set is
base ∪ additions − subtractions. The base is an existing population, sampled one of two ways: a snapshot (items, dateGroups), resolved when the condition is authored and stored as its members, or live (source), a formula resolved when the condition is evaluated. additions are values the author typed, and subtractions are members taken back out.A filter's values list is a snapshot of its column. A validation's typed list is additions with no base, and a validation's range is a live base. Every part is optional and they combine: a range plus a typed
Otherissourceandadditions.Each part matches by its own rule, the one Excel applies to that kind of list:
itemsUNIQUEtells apart), or shows as one under byDisplaysourceMATCH(value, source, 0)finds it;*,?and~in the value are wildcardsadditionssubtractionsAn empty cell is not a value and is no part's to match: the condition's
includeBlanksdecides it.