# Guidelines

Applying a CM patch install package to QA or production app servers is the same as for release install package. That is, it is done simply by executing the install tool from the the package directory.

By using these scripts, implementation developers can prepare an installation package containing the contents of their custom modifications.

Developers need to build a packaging environment on a server of the same operating system platform as used by the target environment to create CM release packages. A version number must be used to identify each custom modifications (CM) release version. Once developers select a version number format, the version number must be stored on the environment in the file `$SPLEBASE/etc/CMVERSION.txt`, to achieve this place `CMVERSION.txt` file in `etc` subdirectory in your patch directory.

Implementers are strongly recommended to use CM packaging utilities for implementation delivery to customer site. It will ensure the correct installation complying with base product rules and will keep an environment upgradable.
Note: Web files can be packaged also in archive war format (if `$isExpanded` environment variable is set to `false`), in which case it is not possible to just manually copy changes to the directories.
Parent topic: App Server CM Packaging Overview