On this wiki, saving an empty page deletes the page and saving an empty file deletes the file.

Using the “titan” command, for example:

$ touch empty
$ titan --token=hello --mime=image/png titan://transjovian.org/file/test empty
20 text/gemini; charset=UTF-8
# test
The file was deleted.

First, create an empty file called “empty” using “touch”. Then, when using “titan”, make sure you use a MIME type that looks like it would result in a file upload and specify the “empty” file for upload.