Mcnasty - we are 0SH, but as others have said it is an agreement, and it doesn't work unless you know both sides will respect it. If a team is not 0SH, we will fill SHs as appropriate. If a non-0SH team is interested in trying it, they can reach out to us, through the forums, discord or line. I will often try to negotiate 0SH terms even with non--0SH teams if I can find a contact; but no one should assume it is automatic unless they have joined the group as well.
This isn't unilateral disarmament; like any treaty it only applies when both parties agree to it.
Having it in the name or motto is just an easy shortcut to help us know which teams are part of it. Even when we see it there, we still verify it against the master list - some teams try to exploit it, and are included on a blacklist of teams that do not honor their agreements.