CSI

abbreviation for Church of Scientology International, the mother church which exercises ecclesiastical authority over all churches and missions of the Scientology religion. —Staff Status I Glossary (approved 25-9-90)

abbreviation for Church of Scientology International, the mother church which exercises ecclesiastical authority over all churches and missions of the Scientology religion.abbreviation for Church of Scientology International, the mother church which exercises ecclesiastical authority over all churches and missions of the Scien tology religion. -It is also applicable to any other Scientology organization and has thus been reissued to "All Orgs." - CSI HCO PL, Non-Scientologist Staffabbreviation for Church of Scientology International.