I've been thinking about this RCF for a while now: https://wiki.php.net/rfc/trailing-comma-function-args
It just doesn't seem necessary - the only time I've ever found something like this to be necessary, is when a function takes closures or other very long arguments, some of which are optional... but actually, writing this in a VCS-friendly way is already possible: $tree->traverse( $tree , function($node) { // ... } ); ... version 2 ... $tree->traverse( $tree , function($node) { // ... } , function($node) { // ... } ); This actually comes out more legible, in my opinion. What really irks me about this patch, is that the trailing comma implies that another optional argument may exist - it really doesn't make the code more intuitive to read. The example on the page (using fopen) really isn't a realistic use-case - who would break a couple of simple arguments into individual lines like that? Just my two cents... - Rasmus