Is there a good source for your first definition? I've never come across this distinction so directly before, and the line between the two is still a little blurry. I hate to get all [citation needed] on you, but it just seems to me that the 'institutionalized system' is nothing more than the vast repetition of many 'arbitrary actions'. Is there a simple textbook example contrasting the two?

Take a look at the sociological definition of racism on the Wikipedia article: http://en.wikipedia.org/wiki/Racism#Sociological

Hey thanks, that's definitely helpful. I wanted to read the Cazenave paper (paywall), but 'centrality' led me to a Google Book [1] which briefly explains MMRI (salience, centrality, regard, ideology). Understanding the differences between these basically answers my question.

1: Culture, Motivation, and Learning: A Multicultural Perspective edited by Farideh Salili, Rumjahn Hoosain, p. 327-328