The Spill Principle
A dynamic array formula written in a single cell automatically fills adjacent cells. If a cell in the spill range is occupied, Excel returns #SPILL!: clear the range rather than shortening the formula.
FILTER Replaces Manual Filtering
FILTER(A2:D500, (C2:C500="Overdue")*(D2:D500>1000)) returns a live table that updates as soon as the source changes. Multiplication acts as a logical AND, while addition acts as OR.
Combining UNIQUE and SORT
SORT(UNIQUE(B2:B500)) builds a clean reference list, ideal as a source for a data validation dropdown that updates itself automatically.
Compatibility
These functions do not exist in Excel 2016 / 2019. A workbook shared with older versions will display #NAME?: plan a fallback version using INDEX/MATCH.