Vtcs2.rar -

: Does this involve adding a feature to how you manage or pack .rar files within a specific utility?

: Are you looking to create a specific design feature (like a toolpath or a shape) within a project file that was shared as a .rar? VTcS2.rar

That's a very specific file name! To make sure I'm giving you the right steps, I need a little more information. : Does this involve adding a feature to

Could you clarify what kind of you are trying to create and what software you are using to open that .rar file? To make sure I'm giving you the right

: Is this a source code archive where you want to add a new functional feature to the program?

The file could be related to a few different things, and the process for "creating a feature" depends on which one you mean:

7-Zip / Feature Requests / #1198 Option to create RAR files?