The last word of a title should be capitalised, but when the last word is a preposition and there is a multi-word preposition before (i.e. not including) the last word, then the last word isn't capitalised.
Contrived example:
>>> titlecase "far from perfect: things to complain about"
"Far from Perfect: Things to Complain about"
but the result should be "Far from Perfect: Things to Complain About"
The last word of a title should be capitalised, but when the last word is a preposition and there is a multi-word preposition before (i.e. not including) the last word, then the last word isn't capitalised.
Contrived example:
but the result should be
"Far from Perfect: Things to Complain About"