@Override
    public void prepend(DocWriter writer, ShapeSubheadingSection section) {
        writer.writeBadge(NoticeType.IMPORTANT, "RETRYABLE").write("\n");
        if (section.shape().expectTrait(RetryableTrait.class).getThrottling()) {
            writer.openAdmonition(NoticeType.NOTE);
            writer.write("""
                    This is a throttling error. Request retries in response to this error should use exponential
                    backoff with jitter. Clients should do this automatically.
                    """);
            writer.closeAdmonition();
        }
    }
This adds badges and notices to errors that are retryable.
smithy-docgen/src/main/java/software/amazon/smithy/docgen/interceptors/RetryableInterceptor.java