From Ajax Patterns
Archived VersionThere's an archived version of this pattern
available, taken from the Ajax Pattern book draft, showing roughly how it appeared before the page became publicly
You want the user to rely on the system to capture the input, but not all input is immediately submitted because you are using SubmissionThrottling or ExplicitSubmission.
Provide hints that indicate what's synchronised and what's pending. For instance, use a different background colour on text fields. This is important if you are using Explicit Submission or Throttling with a long period.