Not all projects are created from scratch. In fact, most are not. Often, existing resource libraries can be used to drop-in complex functionality, such as DHCP, SNTP and other protocol implementations.

When using such a ready-made library, it may be useful to "lock" its file within TIDE and thus prevent accidental modification and clearly mark it as a resource library (or a third-party resource library).

This feature may also be used by vendors providing Tibbo BASIC libraries: They can provide a demo project with the library files locked and implementation files open for editing. This helps customers tell them apart.

To lock a file, simply right-click it in the File Explorer and select Lock File:

When viewing a locked file in the code editor, its background is grayed out:

And when you try to type in it, you get the following prompt:

Another way to unlock a file is to right-click its entry in the tree and uncheck Lock File.