# Write revisions

After a write, a client can make sure its next read sees that write rather
than an older cached copy. Every write returns a `Jadpo-Revision` header,
and browsers get the same value as a cookie. A client that sends it back
skips caches ([Reads and writes](reads-and-writes.md)); one that does
not may see a cached copy up to its `keep:`.

> The `Jadpo-Revision` header isn't built yet: it comes with caches.