{Key--value setting handling in the kernel}
{Joseph Wright}
{\LaTeXe\ introduced class and package setting in the optional arguments 
to \cs{documentclass} and \cs{usepackage}. To date, these were designed to 
handle simple keyword-based option. Over time, packages have extended 
the mechanism to accept key--value (keyval) arguments. Recent work by 
the team brings keyval handling into the kernel. This brings the added 
benefit of allowing repeated package loading to avoid clashes. Here, I 
will look briefly at the background, then explore how to use the new 
mechanism in package development.}