[IanCal]

That means I can't use any kind of generic retry / back off code because I've now got to start dealing with your custom errors, and if you have html versions of the info Google will start demoting you.

Just add a code, it's seconds of work.

[speedplane]

You're assuming you want your API to work with a specialized crawler, like Google-bot. If that's important, then sure, design your API so Google-bot can crawl it nicely, but then it's Google designing your API, not you.

[kiallmacinnes]

I think you missed his primary point. By doing what you describe above, generic client side code to handle retries/backoff etc etc is rendered useless. Your users now have to implement something custom for this (and, if your doing network operations and DONT do this, you likely don't have a very robust system).

[IanCal]

> You're assuming you want your API to work with a specialized crawler, like Google-bot.

Not really, I just don't

In general, the key point as about working in a generic way, given that it's so simple.

I don't like the idea of returning a human readable message that says there was an error but a machine readable message that says everything was fine. I have far too many cases of having to deal with human text explaining that a value is missing already in my data.