You may want to provide other ProTrader users with access to your script in a secure format preventing them from being able to see your proprietary source code. For this case ProTrader Desktop provides own compiled format (PCM file) to protect your MQL, PTL or EL scripts.

In case of using .NET scripts you can export your script as a compiled Microsoft .NET assembly (DLL) file. 

A compiled version of the script (.dll or .pcm) is created automatically after each Compilation. Compiled version of your scripts is saved in My Documents\<ProTrader Folder>\My scripts\bin\

Protection

If you want to distribute your script as a comercial developer, you can protect your MQL, PTL or EL script with a copyright, version, secure password and trial period.
Create a New Module and folow Master Wizard steps to set security settings. 

Also in General Settings you can set the cipher method to protect your inellectual properly. Choose MD5 or RSA for best secure.

All .NET DLL files are compiled which prevents users from being able to see your proprietary source code, but they are still subject to decompilation and reverse engineering attempts. 
For additional protection layer for .NET Scripts we sujest to use 3rd pary obsuscation and protection tools. You can choose any available tool on your own risk.