The general consensus tends to be that boundaries are limits that a person puts down. They come in two varieties:
Tripwire Boundaries are boundaries you establish to monitor a situation. This can be to gauge if a person can be trusted or if someone is attempting something. Fundamentally, these boundaries exist to help you look for behaviour that would indicate possible concerning behaviour. You can tell the other person about the boundary, but there is no fixed penalty for breaching it.
A Reactive Boundary has a fixed response, and is therefore far more effective in protecting yourself. A good reactive boundary will stop the unwanted behaviour without unreasonably limiting anyone involved. They are most effective if stated clearly to the other party.
As such, from our perspectives:
Example boundaries would be:
Notice how these boundaries are protecting the person setting the boundary, and not setting any limits on the other person's personal freedom. They are reactions to your own safety and comfort being breached.
This is an ultimatum. Ultimatums are useful in desperate situations to resolve an unfair conflict, but often resort to escalation. After enacting this ultimatum, both of you will be sad and have lost something. You do not get your ball back by enacting this ultimatum.
This looks like a boundary, but the demand on the other person is unfair. Organisations often include non compete clauses in contracts, but even by free market capitalism’s own standards, this is unacceptable, as it stops the market from being free.
Aggressive tactics will build a hostile environment, breed resentment amongst those involved, and encourage them to leave.
This is a threat. A boundary is something you do to yourself, your environment, or in your space. A punch is an act against the other person.
A boundary should never need the other person to do anything to enforce it. It should be an action you take in response to their disrespecting the boundary.
You should ALWAYS enforce the boundary unless you have a conversation about an exception with the other person BEFORE they act.
Yes, even if the person believed they were helping you, you are a person who stated a clear boundary, and that should be respected.
Failing to enforce a boundary, will weaken all your boundaries. This is how you get a reputation as a pushover.