It seems that the Social Security Office in Orihuela is temporarily out of stock of the plastic cards they need to issue to people wanting to travel abroad (the Tarjeta Sanitaria Europea).
For the moment they are issuing temporary paper documents that provide cover for three months. Presumably when they have a new supply of cards they will issue the one year tarjetas again (hopefully in three months when the paper document expires!).
The Tarjeta Sanitaria Europea is the equivalent of the old E111 of EIHC card that you used to carry when you went on holiday. It enables those of us who have transferred to the Spanish health system to get treatment in other European countries.