Not exactly...
Be careful about editing and re-naming CORE files...
CORE files should be lefyt intact when there is an over-ride possibility available.
ALL zencart stores should work off a CUSTOM template (See FAQ for setting this up). The vast majority of files that ever need to be edited by most store owners are files that should obey the over-ride principle.
Basically, the over-ride principle is this...
By having a CUSTOM template, when zencart looks for various PHP (and other) files, it will FIRST look in a custom template folder.
If it finds the PHP file it needs in that folder, then that is the file it will use.
If it does NOT find the file it is looking for, then it will use the CORE file instead.
So you only ever create a custom (over-ride) file when your edits depart from the core equivalent.
FOR EXAMPLE:
I install and configure a CUSTOM template called patches.
Let's say that I want to change the DEFINE for the following line:
define('TABLE_HEADING_COMMENTS', 'Special Instructions or Comments About Your Order');
I discover that the line is contained in:
includes/launguages/english/checkout_shipping.php
That is a CORE file.
So I makev a copy of that file and edit it, changing the line to:
define('TABLE_HEADING_COMMENTS', 'Please insert any comments, and - if applicable - your Purchase Order Number');
Then I save the file and FTP it to:
includes/launguages/english/patches/checkout_shipping.php
This is my OVER-RIDE and because it is in an over-ride folder, zencart will use it before using the CORE file of the same name.
If I edit this again and make a big botch up I can recall the CORE file, copy it and edit again.
The CORE file has retained its integrity as it never gets edited.