I use the Alpine email software, which is successor to Pine. I mostly like it, but its implementation of "sort by subject" is broken and annoying.
It is documented that Alpine will strip "Re: " and variations from the start of a subject line before sorting, and that seems like something I would reasonably want: replies end up getting sorted with the things they are replies to, instead of all being grouped confusingly under "R". However, what is undocumented and unwelcome is that Alpine will also look for and remove strings enclosed in square brackets, which are typically used to identify mailing list messages. I subscribe to several mailing lists that identify themselves by square-bracketed tags at the start of the subject line while leaving the From: headers unchanged (messages are from the person who sent them instead of from the list). If subject sort worked, then as a natural consequence of how string sorting works, I could group all messages from the list together, sorted within the group by the rest of the subject. But because square-bracketed tags are silently ignored, I can't do that, and there is no way to group the mailing list messages together. There is no option to make subject sort sort on the actual subject, no really, the string that is in the Subject: header and not a munged version.
Fixed by deleting lines 4562 to 4565 of imap/c-client/mail.c in the Alpine 2.00 distribution, which check for square brackets and invoke mail_strip_subject_blob().