What is meaning of this code syntax?

[don]

Hi,
I’m beginning to reacquaint myself with php after many years by reading the code of a fellow I hired to write it. The goal is to completely understand every line. I know what echo does.

I can find no reference in the php.net manual to this long underscore in the construct:

<?php echo __( 'Video Stats Reports', 'rankr'); ?>

What is the significance of it?
Thanks!

[phdr]

It’s a custom function, either from a framework or stand-a-lone. It probably applies htmlentities() to the value, but since it accepts two inputs, it could actually be doing anything. In any case, its definition exists somewhere in the project’s code.

[don]

Aha!
Thank you for that.
Much appreciated!