Or if it helps to remember it in a more PC context: Only Boys Accepting Feminism Get Kissed Meaningfully(E is a relatively new addition for red super giants?). This is the scale that is used to classify a star's spectra. More info can be found on my About Stars Page:
http://www.absolutebeginnersastronomy.com/aboutstars.html
Here is a diagram taken from the page that illustrates how the scale moves from hot brilliant blue spectra(O), to cooler, less luminous red(M). Also it shows the life and development/death of stars on an H-R diagram:
Richard Snow
