Post card with franchise mark "XIII Cuerpo de Ejército / Jefatura de Sanidad" sent by a doctor in the Field Hospital of the XII Army Corps, Base Turia Nº 3, CC12. No postmarks, but text dated in Hellín on September 27, 1937.
Stationery post card Edifil 75 upgraded with two stamps 5c Edifil 681, from Valencia prison to Madrid, with Valencia postmark partially readable and text on the back dated on April 22, 1937. The sender is Luis Barrero, and he gives his sender info on the front: 4ª 472, wich is 4th Gallery, Cell 472.
Stationery post card Edifil 75 to the prisoner Joaquín Juncosa Molins, in Casa de Trabajo, Alcalá de Henares. No postmark, but text on the back dated in Madrid on January 2, 1937. Mark "CENSURADA" in blue and "BREVEDAD / EN LA CONTESTACIÓN".
Cover to Mollet del Vallès with very rare franchise mark "Columna Cultulra y Acción / Roja y Negra / Franqueo / AIT - CNT - FAI", Content dated on February 20, 1937 in Benastár, Huesca. The letter gives the sender's info: "Ejército Popular de Catalunya, Compañía Granollers".
Cover from Calanda, Teruel, to Mollet del Vallès, with mark "Grupo de transmisiones / y señales" used as censor, plus pencil note "Censura Guerra" and signature of the censor. Unreadable date on postmark, but content dated on September 11, 1937.
145 Brigada Mixta mark used as franchise on post card from Codo, Zaragoza, to Mollet del Vallès. Sender's info reads "145 Brigada Mixta, 4th Battallion, Gun Machine Company, Delegation in Alcañiz, Teruel". Text dated on October 23, 1937.
Milícies Antifeixistes de Catalunya field post card to Barcelona, with very rare mark used as franchise reading "División Francico Ascaso / Regimiento / Nº 1 / Durruti / 3º Batallón". No postmark, but text dated on June 13, 1937.
Cover with letterhead Socorro Rojo Internacional, Correspondencia del Combatiente from the front to Madrid, with postmark dated on June 26, 1937. Sent by the soldier Carlos Pascual, 28 Brigada, 2º Batallón, 4ª Compañía.
Registered cover from Las Navas del Marqués to Villaverde de Medina, with mark "Milicia Nacional / Batallón Cruces Negras de la Victoria Nº 1 / Ametralladoras", Villaverde censor mark Heller V95.1 and railway transit backstamp.
Air mail cover from the Madrid front to Gibraltar, with special field post postmark "FRENTE DE MADRID / CORREOS / 23 SET 1937 / ESTAFETA Nº 19" and Madrid censor mark Heller RM1.1.. Madrid air mail backstamp and mark "Via Marseille y Cerbére".
Stationery post card Edifil 75 uprated with 10c Edifil 682 to the prisoner José Luis Estrada Segalerva, falangist, lawyer and poet imprisoned in General Porlier street prison of Madrid, 3rd Gallery. Postmark "Sucurcsal Nº 9 Madrid" from May 3, 1937 and censor mark of the prison "SED BREVES EN LAS CONTESTACIONES".
International Brigades, cover to a brigadist, Perdo Puigdemont, "45 División, Plaza del Altozano Nº 12E - SRI Albacete". The code 12E was for the 12th Brigade General Staff. Pair of 30c with one bisected and Torredonjimeno postmark.
Post card franked with 25c Edifil 667 and Murcia postmark dated on Nov. 12, 1937, from the provincial prison to the same city. Sent by Emilio Díez de Revenga y Rodríguez, lawyer and son of Murcia's mayor Emilio Díez de Revenga Vicente. Sent to his wife María Josefa Torres Fontes.
Cover from Saint Etienne, France, to Bilbao, with was Nationalist zone, but missent to the Republican zone and there censored with Valencia mark Heller RV2.4 and returned to the sender with mark "Retour a / l'envoyeur". Very interesting example of disruption of the postal services due to the war.
Cover from Centuria Ferrer Guardia, Grupo Ametralladoras in La Escala (Girona) to Barcelona, with franchise mark on the front and the back "Centuria Ferrer-Guardia / FAI / CNT - AIT / La Escala". It contains a post card from Empuries archaeological site with the text. Extremely rare.
Air mail cover from Tarancon to Paris, with local Pro Komsomol J.S.U. Tarancon Allepuz 1. Postmark dated on July 8, 1937 and censor mark from Valencia Heller Rep. RV2.4. Arrival backstamp from Paris, Rue Singer, July 13, 1937. RRR.