Harradine (1987) reports that
"as early as 1888, the court of Spain were informed by the general directors of the post of both Antilles and Oceania, through the minister of posts, that almost all kinds of stamps, both postal and fiscal were being used in the colonies to supply the ever-increasingn eeds of the public to frank mail matter. The question of new postage stamps for use in these colonies was then put before the legislative body.
Prolonged discussion dealt mainly with the availability of new stamp supplies due tot he recent death of King Alfonso XII, plus the suggestion made by some members that the effigy of the regent, Queen Christina, should be used on a set of new stamps. The legislative body concluded that, due to the constitutional laws of the kngdom, the bust of the 'baby infant king' should be desinged and printed on all stamps of the realm of Spain and her colonies.
Design of the new stamps was entrusted tot he experienced old desinger Sr. Prado..."
Details of the supporting documentation to the above notes are not currently known.