How long does Mobile Safari keep read items of Reading List in cache? In iOS 6 the Reading List features has the ability to cache pages for offline viewing. I'd like to know how long these pages stay in the ever-growing cache of articles. Since I use this feature quite a lot I wondered if I have to delete this cache every so and so often. That's not very practical though since it will also delete the cached copies of unread items.

I know that Mobile Safari keeps its history only for 7 days, so I assumed that there might be a similar mechanism that clears out read items from the Reading List cache. However, I found an item that is probably 9 days old today while I turned on Airplane Mode and browsed through the list of all items only to find old ones that still have their data in the cache.

So in short: does anyone know if (and when) this cache clears read items?
You have to remove an article from the reading list to purge the contents.

I suppose there is an implied storage limit since you would run out of space on a device once the cached pages exceed the local storage capacity and/or the capacity of iCloud to manage the content across devices.

I haven't tested it, but iOS has the ability to mark some content as cloud backed / temporary and these articles might get culled if you reach a low storage watermark on iOS, but I've never witnessed that happen even on devices where I've run quite full.