Meaning of "Mark as locked"?

An RTF file marked as LOCKED cannot be edited in Devonthink. However, when taken into an external editor, it can be edited and saved back to Devonthink, overwriting the original. Is this what supposed to be? Similarly, a PAGE file can always be modified with the external program even when the file is LOCKED. Therefore, is it correct that there is no protection against modification by external editors even when a file is LOCKED?

A file marked as LOCKED can be moved into the TRASH, but it cannot be deleted from the TRASH. However, if there are locked files in a folder moved to TRASH, and the folder is not locked, then the whole folder containing the LOCKED files can all be deleted. Is this the intended behavior?

It’s only an internal protection, preventing editing and deleting.

I can’t reproduce this over here and actually it shouldn’t be possible. Do you have some steps for me to reproduce this?