I can only get output files with encoding utf-8 no matter what I do. Because of this I don’t get valid XML files. Encoding should be ISO-8859-1. I’m using Quip (command-line interface) with Tamino and all the files in Tamino are with encoding ISO-8859-1.
As you have noticed currently quip does not have any support for encodings. It cannot read general unicode encoded documents but just 8 bit encodings. Furthermore there is no way, how to specify the desired encoding for the output file or to specify the encoding of ther query file itself. (and there is not yet any section about these issues in the XQuery recommendation draft. Therefore, currently QuiP simply assumes that the output is uft-8, which sometimes is, as you have noticed, a lie. To brighten things up: we are currently working on a unicode version of quip.