nl_tokens: Excludes arrow keys delete backspace enter space bar . Ref : https : // developer . mozilla . org / en - US / docs / Web / API / KeyboardEvent . keyCode
pl_tokens: function isSpecialKey ( key ) { return ( ( key <= 47 && key !== VK . SPACEBAR && key !== VK . ENTER && key !== VK . DELETE && key !== VK . BACKSPACE && ( key < 37 || key > 40 ) ) || key >= 224 || // OEM or non-printable ( key >= 144 && key <= 150 ) || // Num Lock, Scroll Lock, OEM ( key >= 91 && key <= 93 ) || // Windows keys ( key >= 112 && <mask> <= 135 ) ) ; // F keys }