Odd behaviour with has key - wide character

Does the letter "v" have any significance when creating a hash key? The following code snippet does not behave as I expect it to:- %H = (v365, 3); print keys %H; When run it outputs Wide character in print at wide.pl line 4. ŭ When the key name is changed to "va365" it prints "va365" as I expect. What is special about just v followed by numbers?