GCF: Gatekeeper Confirmation
GCF: Global Certifications Forum
GCHQ: Government Communications HeadQuarters
GCI: General Circuit Interface
GCI: Global Customer Interface
GCI: Graphic Character Internal
GCI: Ground Controlled Interception
GCL: Generic Control Language
GCL: Global Control and Locate
GCM: Generalized Control Model
GCM: GENIE Communication Manager
GCMD: Global Change Master Directory
GCMM: Generic C Mobility Management
GCN: Ground Communications Network
GCN: Ground Control Network
GCO: Group Chief Operator
GCOM: Global Climate Observation Mission
GCP: Generic Communication Package
GCP: Generic Communication Protocol
GCP: Generic Communications Package
GCPW: Grounded Coplanar Waveguide
GCR: Global Call Recording
GCR: Global Call Reference
GCR: Group Coding Recording
GCRA: Generic Call Rate Algorithm
GCRA: Generic Cell Rate Algorithm
GCS: Gate Controlled Switch
GCS: GENIE Communications System
GCS: Global Carrier Switch
GCS: Global Communications Service
GCS: Governmental Communication Systems
GCS: Ground Control Station
GCSP: General Cluster Server Process
GCST: GSF Call Setup Team
GCT: Greenwich Civil Time
GD: Graceful Discard
GD&R: grinning, ducking and running
GDA: Global Directory Access
GDA: Global Directory Agent
GDB: GNU Source-Level Debugger