Which code # to use in different situations? (general question)

Quick question, should be really easy for someone to answer -

Which code ( ...+1# to ...+7#) should I use for which phones? From what I understand it depends on the country the phone is locked to. When I first unlocked a phone I was told/read to always use ...+7#, but now I see some people recommending only codes +1 and +5 for USA, and +7 for elsewhere. So basically, what codes should I use for USA, and which for UK, etc.

Also, what's the difference between the different codes? Do they unlock different restrictions.

Thanks!

The difference between codes are that they unlock different locks. This does not mean that the locks are radically different: they all do the same, they don't allow you to use a different SIM card, but using different methods, e.g., GID lock, first lock, general lock, etc.

In theory, seventh code unlocks all locks. But there have been cases where seventh code reported "code error" but first code from the same set unlocked the phone, so until there is more work reversing dct4 flash files (which was very difficult until nok5rev and g3gg0 released their tool) we won't know -exactly- how this works.

As a general rule of thumb, USA uses almost always code +1. For UK, codes +1, +2, +5. The rest of the world, code +7.

Now, as we usually say, the first try for USA and UK phones should be +1 code. If that code gives "code error", there is a 99% chance that the rest of the codes from the same set will give code error too. If code +1 gives "phone restriction off", then, as a security measure, also enter codes +5 and code +7. And lastly, try a different SIM to ensure that everything is fine.

Once the phone is unrestricted, the only way to restrict it again is by hardware, so if code +1 was successful, although codes +5 and +7 give code error the phone will not be locked again.

I hope this explains a little.

Best regards
Edge