Typing Nonprintable Unicode Zero width non joiner (ZWNJ) in Ubuntu 14.04

Urdu is written in cursive script, which means that consecutive characters join together and change their shape according to the context. To correctly shape characters a Zero width non joiner has to be used, which can not be typed by a single key stroke like the regular space bar key on the keyboard.

For typing non printable ZWNJ in Ubuntu 14.04 follow these steps:

1. Click the dash and search for Character Map
2. Launch Character Map and click the box next to "Text to copy"
3. Press and hold Ctrl Shift and press U, an underline u will appear
4. Now type the sequence 200C
As the sequence represent a non printable character it will be replaced by ZWNJ and nothing will appear
5. Now click the "copy" button

You can now paste it in the editor using the keyboard shortcut Ctrl+V or via menu

Link to a post on Ubuntu Forum that helped me