The "Ignore prefixes when sorting by artist" option is great. I like that, for instance, The Who show up under "W" rather than "T" without having to change the tag to just "Who." I think it would be good to extend this feature to other fields as well. Album and Title would probably be the most useful, but some people might want to ignore "The" and other prefix words in their custom and/or classification fields as well.
I would suggest changing "Ignore prefixes when sorting by artist" slightly to say something like "Ignore the following prefixes," then the box like there is now where users can input custom prefix words, followed by "For..." and checkboxes underneath it to indicate which fields the user would like to ignore prefixes for. At a minimum, these checkboxes would include Artist, Title, and Album, and maybe even all fields (or at least all text fields).
It would also be nice to be able to specify characters as prefixes to be ignored, even when not followed by a space. For instance, I would like to ignore parentheses so that Blue Öyster Cult's "(Don't Fear) the Reaper" shows up under "D" when sorted by title, rather than being at the top. I don't know if this is a feature that should be added to the "Ignore prefixes" box or if MM should just have an option to ignore all non-alphanumeric characters when sorting.
Does anyone else have any comments/ideas on these suggestions?