| AIE |
Ala Izquierda Estudiantil (Left-Wing Students) |
| ANERC |
Asociación Nacional de Nuevos Emigrados Revolucionarios de Cuba (Association of New Revolutionary Emigrés from Cuba) |
| APRA |
Alianza Popular Revolucionaria Americana (American Popular Revolutionary Alliance) |
| ARG |
Acción Revolucionaria Guiteras (Guiteras Revolutionary Action) |
| BOC |
Bloque Obrero y Campesino (Workers’ and Peasants’ Bloc: Spain) |
| Comintern |
Communist or Third International |
| CC |
Central Committee |
| CDR |
Comité de Defensa de la Revolución (Committee for the Defence of the Revolution) |
| CNOC |
Confederación Nacional Obrera de Cuba (National Labour Confederation of Cuba) |
| CPUSA |
Communist Party of the United States of America |
| CROM |
Confederación Regional Obrera Mexicana (Mexican Regional Labour Confederation) |
| CTC |
Confederación de Trabajadores de Cuba (Workers’ Confederation of Cuba) |
| DOI |
Defensa Obrera Internacional (International Labour Defence) |
| FCT |
Federación Cubana del Trabajo (Cuban Labour Federation) |
| FI |
Fourth International |
| FOH |
Federación Obrera de La Habana (Labour Federation of Havana) |
| ICL |
International Communist League (Bolshevik-Leninists) |
| ILO |
International Left Opposition |
| INRA |
Instituto Nacional de Reforma Agraria (National Institute of Agrarian Reform) |
| KPD |
Kommunistische Partei Deutschlands (German Communist Party) |
| LOR |
Liga Obrera Revolucionaria (Revolutionary Workers’ League: Argentina) |
| M26J |
Movimiento 26 de Julio (26th July Movement) |
| MAFUENIC |
Comité de Manos fuera de Nicaragua (Hands Off Nicaragua Committee) |
| MNR |
Movimiento Nacionalista Revolucionario Revolutionary Nationalist Movement: Bolivia) |
| MR-13 |
Movimiento Revolucionario 13 de Noviembre (13 November Revolutionary Movement: Guatemala) |
| MSR |
Movimiento Socialista Revolucionario (Revolutionary Socialist Movement) |
| OCC |
Oposición Comunista de Cuba (Communist Opposition of Cuba) |
| ORI |
Organizaciones Revolucionarias Integradas (Integrated Revolutionary Organisations) |
Profintern
or RILU |
Red International of Labour Unions |
| PBL |
Partido Bolchevique Leninista (Bolshevik Leninist Party) |
| PCC |
Partido Comunista de Cuba (Communist Party of Cuba) |
| PCM |
Partido Comunista de México (Communist Party of Mexico) |
| POR |
Partido Obrero Revolucionario (Revolutionary Workers’ Party) |
| POR(T) |
Partido Obrero Revolucionario (Trotskista) (Revolutionary Workers’ Party (Trotskyist)) |
| POUM |
Partido Obrero de Unificación Marxista (Workers’ Party of Marxist Unification: Spain) |
| PRC(A) |
Partido Revolucionario Cubano (Auténtico) (Cuban Revolutionary Party (’Genuine Revolutionaries’)) |
| PSP |
Partido Socialista Popular (Popular Socialist Party) |
| PURS |
Partido Unificado de la Revolución Socialista (Unified Party of Socialist Revolution) |
| SGECC |
Sindicato General de Empleados del Comercio de Cuba (General Commercial Workers’ Union of Cuba) |
| SNOIA |
Sindicato Nacional de Obreros de la Industria Azucarera (National Union of Sugar Industry Workers) |
| SWP(US) |
Socialist Workers’ Party (United States) |
| UFON |
Unión Federativa Obrera Nacional (National Federative Labour Union) |
| UIR |
Unión Insurreccional Revolucionaria (Revolutionary Insurrectionary Union) |
| URC |
Unión Revolucionaria Comunista (Communist Revolutionary Union) |
| USec |
United Secretariat of the Fourth International |