Castas

Hello all:
I have been reading the Church Records from Guerrero, Coahuila and came across a term I have not seen before and for which I do not know the colloquial meaning. I can't seem to find a definition online.
The baptism records are from late 1780s to 1820. The term is "havidos por españoles." It is found in several records and is used in reference to the racial status of parents. I assumed it was supposed to be "habidos por Españoles," literally "had by Spaniards," but I still don't get it in this context. Maybe a term indicating Spanish (European) descent of indeterminate nature? I've asked a couple of people I know, but nobody can tell me what is meant in this usage. Can anybody shed some light on the terminology for me?
Thanks, all
-Scott