Thanks for all your suggestions. The problem I'm running into is that this is a client's ISP & their version of Perl, which must be older (see my response to Anonymous Monk above). I'm not sure what version it is, but the 'use UTF8' and other suggestions don't work, they just give errors. I have sent an email to ask if they would upgrade, but I'm not hopeful knowing how isp's are.
Re: international case insensitive searched with Perl
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If you're using the OS installed perl, then an upgrade of it would be unwise. If the ISP has a 2nd install of perl for customer use, great. Otherwise, does your customer have enough space in their account to install their own copy of perl? This could be a great solution. Just don't install it in a directory that is directly accessible by the web server and it's clients.