Null sign

No, you cannot put text with embedded null characters on the clipboard. Let's look at the list of standard Windows clipboard formats. There are a few formats that hold things generally understood as text:

• CF_TEXT (1)
• CF_OEMTEXT (7)
• CF_UNICODETEXT (13)

Every single one of those has this sentence in its definition:

A null character signals the end of the data.

Now, CF_UNICODETEXT keeps its data as UTF-16LE, so it will more than likely have some null bytes, but null characters (two null bytes in a row, basically) will still end the string.

We can only speculate about why null characters aren't allowed in clipboard text, but more than likely it's just because the most commonly-used string processing functions in Windows assume a null character signals the end. The only other way to know where a string stops would be to prefix it with its length.

You can hold graphics on the clipboard even though they likely have null bytes because they get passed around in different clipboard formats (e.g. CF_BITMAP), which have to be understood differently by programs.

Another suggestion is you can also type: Alt + 0216.

Best regards,

Dan

Another suggestion is you can also type: Alt + 0216.

Best regards,

Dan

This is sufficiently rare, and handled in sufficiently many different ways, that you should always state explicitly how you're treating it. In my experience, the most common symbols are:

• $\mathsf{null}$, $\mathsf{nil}$, $\mathsf{NaN}$ or similar on the more computer-sciencey side, and

• $\perp$ or $\uparrow$ on the more logicy side.

  • Note that "$\perp$" is also used to denote contradiction, and "$\uparrow$" is also used as a predicate to denote "is undefined" or "doesn't halt" with "$\downarrow$" denoting "is defined"/"does halt."

But again, I'd explicitly state which you're using - although admittedly multiple of these would almost certainly make it obvious from context.