Read-only files:

Documents in Notepad++ can be marked as read-only, meaning they cannot be modified.

Notepad++ recognizes two read-only states:

• The file in the filesystem is marked as read-only. You can only enable the editing of the file by clearing the read-only flag. You can do so by selecting Edit->Clear Read Only Flag.
• The document in Notepad++ is marked as read-only. You can manually set this option by selecting Edit->Set Read Only. The document in Notepad++ cannot be edited, but if the file exists in the filesystem it will not be marked as read-only, this is just an internal state.