The plan below is available via a link on the members page of the association web site

This note explains the Spanish method of postal addresses, and how this applies to Gata Residencial
(Based on my understanding. I have never found a definitive explanation – Peter Bayliss.)
Note that each house on Gata Residencial is built within a block – or Manzana – of houses. The Manzana or M number, is useful for deliveries, but it not strictly needed for the postal address.
Also, for those Manzanas that contain a community of houses, the postal addresses are listed in the bottom right hand side in the image above.
So for the houses on M20 for example the common address of all the postboxes would be Carrer dels Carrasqueres 15 as shown on the map above.
The most common type of community of owners in Spain is a block of apartments. In this case, the postal address of each apartment would be the street address of the building followed by the number of the apartment e.g “Calle Mayor25, puerta 12”. I believe that Correos in Gata has used the same scheme to number the houses within each community on Gata Residencial.
So for house number 16 in M20 the correct address is Carrer dels Carrasqueres 15,PTA 16.
The situation is complicated however because the builder responsible for “Gata Park” did not ensure that postboxes are provided for these houses. This currently affects houses on M17 and M20. The officers of La Asociación de Gata Residencial have been trying to resolve this situation on behalf of the owners but progress has been slow. Although the postboxes do not physically exist the numbering scheme is used by Correos and other official purposes e.g. SUMA, Catastral.
Note that Carrer dels Carrasqueres 16 is not correct and sometimes could be confused with another house.
For the houses which are not part of a community, e.g. those in Blocks M16 and M19, only the house numbers is used e.g. Carrer dels Carrasqueres 18.
So although Correos know the M numbers, including the M number in the address is not strictly necessary. However it can help to avoid confusion, especially when the postbox number is omitted from the address for some reason. . For example, a letter addressed to M20 Carrer dels Carrasqueres PTA 16 for example should find its way to a house on M20 and not M19.
Note that the address of the main door of your property e.g. for deliveries etc., might be different from the postal address. For deliveries, it is often useful to include the M number in a delivery address.