I'd second this recommendation. Camel case is standard for web services, and I'd use it for all SOAP methods exposed to the user. I'd use underscore_style in your code, per Perl convention. As annoying as it may be to have both styles around, it will help distinguish what's exposed to the user and what's not, and will keep your external interface in line with what SOAP users expect, and your internal code in line with what Perl people expect.