collecting - (RCSD) Spain Regulatory (?) stamp

http://cjoint.com/data/mpbYj2jxEv.htm

I found this stamp and have tried unsuccessfully so far to get some
information about it and similar. I have found lots of legal information
about the Mutualidad Nacional de Previsión de la Administración Local law of
May 12, 1960, such as its applicability in Spain and the Canaries, and the
exclusion from its requirements of local corporations and agencies of
Navarre where a separate but similar law was enacted. The law was intended
to be administered at the municipal (local) level but there is nothing on
this particular stamp at least that reflects geography; so I must assume
that they were available and applicable everywhere.

I cannot seem to find any information about the stamps themselves, such as
how, and how often, and on what they were applied, so any info, even gossip,
would be greatly appreciated.

Thanks in advance.
--
Tony Vella, Ottawa, Canada
http://tv-stamps.shorturl.com