The rewritten Style Guide has an open discussion of the spoiler policy. The current policy will be used if no new consensus is reached. Discuss it here.
For areas that need to be unlocked from the opposite side: 🔒
{{Unlockable|Locked}}
For connections that require certain actions to be unlocked: 🔐+🔐
{{Unlockable|LockedCondition|Instructions|Link to instructions}}
For connections that unlock a bidirectional entrance: 🔑
{{Unlockable|Unlock}}
Documentation (for the above template, sometimes hidden or invisible)