Lam-Alef Expansion
The bidirectional layout engine converts between visual and implicit representation of Arabic characters. The Lam-Alef ligature in visual representation is expanded to <Lam> and <Alef> characters in implicit representation. If there are insufficient blank spaces at the end of Arabic text (i.e., the beginning of the English field) into which the Lam-Alef can be expanded, characters at the end of the Arabic field are lost and replaced by the <SUB> control character.
To ensure a sufficient number of spaces at the beginning of the field, Personal Communications protects one space for each <Lam-Alef> character. An error message is returned if you try to enter a character in the protected space.
In the following example, entering one <Lam-Alef> character at the beginning of the Arabic field results in the protection of one space at the beginning of the English field.
| Position | 1 | 2 | 3 | 4 | 6 |
| Character | None allowed (protected) | open | open | open | <Lam-Alef> |
In this example, two <Lam-Alef> characters have been entered, so Personal Communications protects two spaces at the end of the Arabic field.
| Position | 1 | 2 | 3 | 4 | 5 |
| Character | None allowed (protected) | None allowed (protected) | open | <Lam-Alef> |
<Lam-Alef> |
- If there are no more unprotected spaces available in a field and you try to enter any additional characters, you will receive an error message and the keyboard will be locked. Click Reset to unlock the keyboard.
- For the Paste and Delete functions, if the leftmost space in the field (position 1 in the above examples) is not blank when the <Lam-Alef> character is entered, you will not be able to enter the <Lam-Alef> character and Personal Communications will return an invalid key error message.
- This expansion feature is not supported for Windows Terminal Server.
You may enable this expansion protection feature from the Settings → Appearance → Display Setup menu.