Product xcart 5
 

It will affect all of them yes but you can limit which ones are affected with your custom module. In XC5 you can't just go an change some code - it has to be done with a module or you lose changes on next upgrade.

Re: Product xcart 5
 

Hi @thanhlan2103,

Welcome to X-Cart forums and thanks for your message!
It is indeed a good advice for developers who started learning X-Cart 5.
When you separate your code from the core, it allows smooth upgrades and makes sure that your changes will not be lost.

Tony