Ethics opinions are guidance by bar associations on ethical attorney conduct. They are not binding on courts but are frequently cited by them.
Both the California bar and various local bar associations within California produce ethics opinions.
The best starting point for researching these opinions is the index to the California Compendium on Professional Responsibility:
The full text of decisions from the California bar association are readily available online:
The full text of decisions from most local bar associations are also readily available online:
Formal ethics opinions of the Los Angeles County Bar Association are available through a mixture of print, opinions posted by the Los Angeles County Bar Association, and opinions posted by the Loyola Law School library:
Informal ethics opinions of the Los Angeles County Bar Association are available in print: