Compatibility Standard¶
State the compatibility target explicitly, per product¶
Every product must state, in its own specification, exactly what environment it is built and tested for — at minimum, which Excel version/subscription tier (e.g., "Microsoft 365 desktop, current channel") is the baseline. This baseline should not be left implicit or assumed to be "whatever version the builder happened to use."
Cross-version and cross-platform claims require actual testing¶
Any claim that a product works in an environment beyond its stated baseline — an older Excel version (e.g., Excel 2019/2021 perpetual license), Excel for Mac, LibreOffice Calc, or via import into Google Sheets — must be backed by an actual test in that environment. This includes checking:
- Whether formulas (especially newer functions like dynamic-array functions,
XLOOKUP,LET,LAMBDA) evaluate correctly or fall back/error. - Whether formatting, conditional formatting, and data validation render as intended.
- Whether named ranges, Excel Tables, and structured references behave consistently.
- Whether macros (if any) run at all in the target environment.
Untested compatibility must not be claimed¶
If a product has not been tested in a given environment, no document, listing, or support material may state or imply that it works there. The correct default when compatibility is unknown is silence on that environment, or an explicit statement that compatibility outside the stated baseline is untested — not an optimistic assumption. This applies to AI-generated content as much as human-written content; see ../ai/guardrails.md.
Where this matters most¶
Compatibility claims are especially consequential in marketplace listings (see marketplace-listing-standard.md), where an inaccurate compatibility claim can lead directly to a customer purchasing a product that doesn't work for them and requesting a refund or leaving negative feedback.