Glossary heading
Shelf life
This publication's own classification of how long each field it files can be trusted for.
Also written: how long a fact keeps
Not every fact rots at the same speed. The year a company was founded does not move. A permit is issued for a calendar year. A price is a snapshot of a Sunday. A promotion is a marketing decision that can change on a Tuesday without an announcement, and it is the reason this publication does not build pages around offers.
Four classes are used across the cross-reference: durable, annual, seasonal and perishable. Every thread declares which one it belongs to, at the top of its own page, so a reader arriving two years from now can tell at a glance which cells are still worth leaning on and which need re-reading before anything is done with them.
The classification is a promise about maintenance rather than a disclaimer. An index that could not say which of its own contents had aged would be no more useful in two years than a page of screenshots.