YOu can even use any charachter that blockland supports, like €£¥#%^*+=?, and as long as you put those characters in array brackets, it will work. you can even use spaces.
==>$val["hello world"] = 1;
==>deleteVariables("$val*");
umwat
My point proven.as long as it is in those [" 's, it will work.The damn ui name tables are made like this.