Classic ASP text substitution and UTF-8 encoding

Question

We have a website that uses Classic ASP.

Part of our release process substitutes values in a file and we found a bug in it where it will write the file out as UTF-8.

Answer 1

UTF-8 does not use BOMs; it is an annoying misfeature in some Microsoft software that puts them there. You need to find what step of your release process is putting a UTF-8-encoded BOM in your files and fix it — you should stop that even if you are using UTF-8, which really these days is best.

But I doubt it's IIS causing the display problem. More likely the browser is guessing the charset of the final displayed page, and when it sees bytes that look like they're UTF-8 encoded it guesses the whole page is UTF-8. You should be able to stop it doing that by stating a definitive charset by using an HTTP header:

Content-Type: text/html;charset=iso-8859-1

and/or a meta element in the HTML

Now (assuming ISO-8859-1 is actually the character set your data are in) it should display OK. However if your file really does have a UTF-8-encoded BOM at the start, you'll now see that as ‘’ in your page, which is what those bytes look like in ISO-8859-1. So you still need to get rid of that misBOM.