Reusing old phones -- reset all before you put them in the storage.

We've accumulated several old iPhones - 4 and 4s. We find a use for them periodically -- as alarm clocks, media players and so on. 

Today I ran into a problem with this that I'd not considered. I went to reuse an old device with a restriction code -- and I couldn't because it was an old code we no longer use. It wasn't in my password store because it was obsolete.

Miraculously I remembered it. Two lessons learned:

1. I can’t delete old passwords. I should know this. I ran into a similar problem years ago when Apple effectively made “mac.com” free again — and I no longer had the password I’d used when I stopped paying for it.
2. You need to wipe phones before putting them in the bin. I was leaving them unwired as an extra backup during device transitions.

PS. Another reason to reset. If you restart an old phone it may register with iTunes and iCloud — and mess up iMessage addressing and iTunes device limits.