I booked CP specifically because they are part of the OneWorld Alliance with American Airlines. After the flight, when my miles didn't post, I was informed it was the wrong fare code. Turns out CP has 21 fare codes, and eight are not eligible for frequent flyer miles. I have flown millions of miles, mostly on American over the past 30 years, and have never known what the fare code even was. I felt duped. Economy seats way too small anyway. I won't be flying with them in the future if at all possible.