UINavigationButton in Tabbar - possible rejection?

Someone wants me to make an App, where the NavigationButton (usually top left) shall be put into the Tabbar (in this case leftmost Button of the Tabbar). I wonder if that might yield a possible rejection.

It reads in the Appstore Review Guidelines:

a) Apps that alter the functions of standard switches, such as the Volume Up/Down and Ring/Silent switches, will be rejected

-> Could that also include NavButtons?

Furthermore:

b) Apps that do not use system provided items, such as buttons and icons, correctly and as described in the Apple iPhone Human Interface Guidelines and the Apple iPad Human Interface Guidelines may be rejected

I do not know whether we crossed the line there.

What's your opinion on thi开发者_如何学Pythons?

I'd say it's a bit of a crap shoot and you need to weigh whether the feature is important enough to possibly delay your release by 2 weeks or more. If you submit it with the feature I would spend some time working on a different solution so that if it is rejected you can submit with the changes right away.

From personal experience, I had an app rejected because they didn't like the image I used on a button since that image was meant to convey "picking a contact for use in the app" not picking a contact to add information too. It was my opinion that this was a petty almost silly thing, but I corrected it and resubmitted. Both reviews took over 2 weeks. So it took me over 4 weeks to get approved.

Apple has gotten better about telling you what won't be accepted, etc. But different reviewers seem to have different opinions. I'd say the description of your feature is likely to be rejected, but you'll never know until you submit it.

Instapaper has a back button in a tab bar at the bottom. I think that if you decide to do this, you shouldn't use the system back button but create your own. Using the system button feels like a HIG violation.