XML is case-sensitive, but you can trySelectNodes("*[translate(name(),'ABCDEFGHIJKLMNOPQRSTUVWXYZ','abcdefghijklmnopqrstuvwxyz') = 'document'] if you are interested in custom function, also seehttp://msdn.microsoft.com/library/default.asp?url=/library/en-us/dnexxml/html/xml10212002.asp
sure, but shouldn't be much, since you need that flexibility, you really don't have much choice, right? you can run some performance testing to see the difference
if you are interested in custom function, also seehttp://msdn.microsoft.com/library/default.asp?url=/library/en-us/dnexxml/html/xml10212002.asp
http://www.w3schools.com/xpath/xpath_functions.asp