Another fun piece of PHP history: The old leaked source code for Facebook's index.php and search.php circa 2007: https://gist.github.com/nikcub/3833406
// Holy shit, is this the cleanest fucking frontend file you've ever seen?!
ubersearch($_GET, $embedded = false, $template = true);
Generally at that time (and for a few years after) you still see a huge influence from C programming constraints in php.
Lot of extremely terse abbreviated variables and explicit looping. And for some fucking reason the pervasive believe that variable names need to be at most either 3 or 6 characters long. (Yes I know the reason it's still bad)
So yeah painful as it is to admit that is well above average expressiveness and readability for php of its era.