When using a multiline edit box like the one in the BIS debug console, it is impossible to insert a carriage return or a tabulation with the keyboard.
In addition, when we copy a text from the clipboard (Ctrl-V), all carriage returns and tabulations are broken.
This is annoying for some very useful community tools. It also corrupts a SQF script pasted in the text box, if it contains inline comments (//).
Implementing these characters will provide a powerful tools to develop scripts in real time ingame.