| Subject | English | Portuguese |
| tech., law, el. | connecting closed distribution system operator | operador de rede de distribuição fechada de conexão |
| tech., law, el. | connecting distribution system operator | operador de rede de distribuição de conexão |
| transp., avia. | dedicated System Panel Operator | operador dedicado ao painel dos sistemas |
| commun., IT | digital stand alone operator system | sistema digital autónomo de operadoras |
| el. | distribution system operator | distribuidor |
| el. | distribution system operator | operador de rede de distribuição |
| energ.ind., el. | electricity transmission system operator | operador da rede de transporte |
| energ.ind., el. | electricity transmission system operator | operador da rede de transporte de eletricidade |
| energ.ind. | European Network of Transmission System Operators | Rede Europeia dos Operadores das Redes de Transporte |
| gen. | European Network of Transmission System Operators for Electricity | REORT para a Eletricidade |
| el. | European Network of Transmission System Operators for Electricity | Rede Europeia dos Operadores das Redes de Transporte de Eletricidade |
| energ.ind. | European Network of Transmission System Operators for Gas | Rede Europeia dos Operadores das Redes de Transporte de Gás |
| gen. | European Network of Transmission System Operators for Gas | REORT para o Gás |
| energ.ind. | European Transmission System Operators | Operadores de Redes de Transporte Europeias |
| energ.ind. | gas transmission system operator | operador da rede de transporte |
| energ.ind. | gas transmission system operator | operador da rede de transporte de gás natural |
| energ.ind. | independent system operator | operador de rede independente |
| commun. | multiple system operator | operador de sistema múltiplo |
| transp., mil., grnd.forc., tech. | operator inducement system | sistema de persuasão do condutor |
| IT | operator of man-made systems | operador de sistemas fabricados pelo homem |
| mech.eng. | operator restraint system | sistema de segurança do condutor |
| nucl.phys. | operator support system | sistema de suporte do operador |
| commun., el. | operator system | sistema de espera |
| fin. | payment systems operator | operador dos sistemas de pagamentos |
| fin. | re-diffusion systems for market operators | sistemas de difusão para operadores |
| commun., IT | stand alone operator system | sistema autónomo de operadoras |
| el. | system operator | operador de rede |
| el. | system operator | operador da rede |
| transp., avia. | system panel operator | operador do painel de/dos sistemas |
| energ.ind. | transmission system operator | operador da rede de transporte de gás natural |
| el. | transmission system operator | operador de rede de transporte |
| energ.ind. | transmission system operator | operador da rede de transporte |
| energ.ind., el. | transmission system operator | operador da rede de transporte de eletricidade |