Insert non-copyable character

I am taking some programming notes, and the source code lines are too long.
I want to insert a character to mark the end of the line when I print the paper, but I want to be able to copy the source code without those characters.

Does libreoffice allow me to do something like this?

UPDATE: I am talking about adding a sign such as ¶ (formatting mark) at the and of all my code blocks. When I print the document, I should see those characters. When I copy a code block from the document, the characters should not be in the clipboard.

Basically, I need to somehow mark the end of the line, for the cases when the line is wrapped.

Are you looking for symbols like ⏎ or ␤? Please edit your question (don’t use an answer) to better describe your expected result. If possible, attach a screenshot or a picture of a hand-written note to give an example. Also, mention your OS and LO version. Solution may depend on the OS.

Not an answer, but some cludge that might or might not be helpful:

If you need the character(s) be only visible in print, then you may use a character style with Hidden font effect: if you set hidden characters to be printed (in OptionsWriterPrint), but not show on screen (in OptionsWriterFormatting Aids), then you won’t see them on screen (and be unable to copy them to clipboard), but have them printed.

The additional drawback is it would be not easy to manage (you won’t see where you had already added the characters, and where you didn’t).

I updated the question.

Comment on your edit: present programming languages are usually “free-format”, i.e. their instructions are not tied to a line and may span freely several line (notable exceptions are shell and Python). In languages for which end-of-line is significant as an end of statment, a common rule is to escape EOL with a reverse solidus \. Why don’t you use this convention to flag line continuation?

This way, you don’t need an end-of-sample indicator because you have the “mirror” flag of “line-too-short”.

Of course, you should also write your code snippets in specific paragraphs, at least styled Preformatted Text so that you precisely control alignment.