Spain is different! This is an often used phrase but it's more than true relating to the postally used date stamps and cancellations.
Where most countries work with one single date stamp for all purposes of the daily work, Spain used (and still uses today) a tremendous variety of different cancelling machines, seperately for registered mail, express mail, printed matters, declared values, ambulant mail, airmail and so on.
To give you a short overview, most of the basic models are shown below. Little by little I'll add more information about the different postal marks and link these new pages with the pictures below. So I ask for some patience. Thanks!
A) Circular and boxed datestamps || B) Registered mail markings [CERTIFICADO]
C) Express mail markings [URGENTE] || D) Insured mail markings [VALORES DECLARADOS]
E) Travelling post offices [AMBULANTE] || F) Airmail markings [CORREO AEREO]
G) Printed matter markings [IMPRESOS] || H) Machine cancellations
I) Official markings [FRANQUICIA] || J) Carteria markings
K) Special markings || L) Others