Ah yes, fair addition there: The language is not assumed to be set in stone forever, but "guided" by certain academic authorities, that try to strike a balance between the system representing the reality of the spoken language and rules being kept standard. We get dictionary patch notes, so to speak.

The Real Academia Española does this job in the case of Spain, and there's an equivalent in each Spanish speaking country, with all belonging to a larger entity.

>Spain: "autillo" but last time I posted it, anthk said it's more complicated

Yup, diminutives are very regional here, one of the easier ways to pinpoint someone's origin: iño is common in the northwest due to influence of Portuguese, -ete in the northeast as an influence of French and Catalan, etc.