+- Follow
+ [Google's timeless documentation guide](https://developers.google.com/style/timeless-documentation).
+ Describe what the checked-in code does. Do not use labels that depend
+ on time, such as "new", "now", "currently", and "previously".
+- Follow
+ [Google's tense guide](https://developers.google.com/style/tense). Use
+ the present tense for general behavior. Use the future tense only when
+ the timing of an action requires it, not for planned features.
+- Keep previous designs, development history, roadmaps, and future work
+ in issues.
+- State exact support and limits instead of labels such as "prototype".
+ Keep implemented, tested, and unverified behavior apart.
+- Keep safety requirements and known limits explicit. For example, say
+ when fake-service tests do not verify compatibility with the live
+ service.
+- Keep compatibility and old-schema details when the code or the
+ migration tests require them. They describe an active contract, not
+ history.
+- Do not remove a warning or claim support only to remove historical
+ wording. Check the implementation and the tests before you change a
+ claim.
+- Compare claims, examples, paths, and links with the implementation and
+ the tests. Make sure that examples use supported interfaces and
+ contain no secrets.