env:<PREFIX><INSTANCE>_... is the per-instance convention for every prefix of a
driver's scope (OTOPCUA_GALAXY_, GALAXY_MXGW_, OTOPCUA_OPCUACLIENT_,
OTOPCUA_HEIDENHAIN_), INSTANCE = a driver id or name upper-cased with every other
character as '_'. A variable whose part after the prefix equals or starts with
(at a '_' boundary) ANOTHER same-type instance's id or name is refused with
CredentialReferenceOtherInstance at save, deploy, Test Connect and browse - the
same DriverCredentialPolicy.DescribeOtherInstanceProblems the secret: rule uses
(now over CollectInstanceReferences / ReferenceNames). Another-instance matches
win over the owner's, as for secrets. Shared variables that name no instance
(GALAXY_MXGW_API_KEY) keep working. HasInstanceSegments now also gates on env:,
so an env:-only browse needs the ConfigDb (fail-closed without it).
Co-Authored-By: Claude <noreply@anthropic.com>
Joseph Doherty
4a6229e4d2