What is the .ph extension

I have noticed that in my includes/templates/template_default/templates folder there are some files with the .ph extension, namely:
tpl_product_free_shipping_info_display.ph
tpl_modules_products_featured_listing.ph
tpl_modules_products_quantity_discounts.ph
Are these corrupted files?
If not, how do they work?
Thanks.

Zen Cart does not use .ph file extensions.
Those are either displayed wrong, or maybe were renamed as backups.
Zen Cart would not use those files. It expects .php files.

DrByte:

Zen Cart does not use .ph file extensions.
Those are either displayed wrong, or maybe were renamed as backups.
Zen Cart would not use those files. It expects .php files.
Thanks for the swift clarification.
Those files are not backups of any other .php file with the same name, probably corrupt.
My webhost uses a decompress/ftp utility called Webshell which does all sorts of weird stuff.
Won't use it any more, will simply decompress locally and ftp with Filezilla.
Will replace those files from a new decompressed 1.3.7.1.
Best regards.

To be safe, I would think you would best re-upload the entire installation, unless you have a lot invested in the particular files on your server already. If Webshell can truncate file extensions, who knows what little things it might do that you won't discover until you have fully customized your site and have gone live...

gjh42:

To be safe, I would think you would best re-upload the entire installation, unless you have a lot invested in the particular files on your server already. If Webshell can truncate file extensions, who knows what little things it might do that you won't discover until you have fully customized your site and have gone live...
You are right of course.
Actually, this is what I intend to do, in order to prevent future complications.
Webshell has size limitations and times out, truncating files or simply not decompressing them at all.
I am going to enter a ticket with the webhost letting them know that the utility is not reliable.
Luckily I caught all this in early stages of development and can start over.
Thanks a lot for the sound advice.