A long time ago there was a discussion here about typing characters from the International Phonetic Alphabet in Scribus. At the time I had an RTF file with a table containing all the codes, but I was unable to get it to people because of difficulties at my personal web site at my university.
I am happy to report that there is now a comprehensive website that contains my RTF file, and tons of other details on how to enter IPA (and lots of other characters) into Scribus: http://ipa4linguists.pbwiki.com I hope Scribus users fine this helpful.
