Editing Call forwarding (section)

===Mobile (cell) phones===
For GSM/3GSM (UMTS) phones, the [[Global System for Mobile Communications|GSM]] standard defines the following forwarding [[Unstructured Supplementary Service Data]]. These were developed by ETSI and are based on standard European diversion codes and are similar to those used on most landlines in the EU:<ref name="geckobeach">{{cite web | url=http://geckobeach.com/cellular/secrets/gsmcodes.php | title=GSM feature codes | work=Tips and Secrets | publisher=Gecko Beach | access-date=2010-07-26}}</ref>

{| class="wikitable"
!Forward service!!width:100px|Activate!!width:150px|Cancel & Deregister!!width:150px|Cancel & Retain!!width:100px|Status!!width:100px|Reestablish
|-
!colspan="6" style="background:#FFFFCC;"| Unconditional forwarding
|-
|All calls ||align=center| *21*[phone number]# ||align=center| ##21# ||align=center| #21# ||align=center| *#21# ||align=center| *21#
|-
!colspan="6" style="background:#FFFFCC;"| Conditional forwarding
|-
|If busy ||align=center| *67*[phone number]# ||align=center| ##67# ||align=center| #67# ||align=center| *#67# ||align=center| *67#
|-
|If not answered (see below for custom delay)||align=center| *61*[phone number]# ||align=center| ##61# ||align=center| #61#
|align=center| *#61#<br>(incl. time delay)
|align=center| *61#
|-
|If out of reach ||align=center| *62*[phone number]# ||align=center| ##62# ||align=center| #62# ||align=center| *#62# ||align=center| *62#
|-
|All forwards ||align=center| *002*[phone number]# ||align=center| ##002# ||align=center| #002# ||align=center| *#002# ||align=center| *002#
|-
|All conditional forwards ||align=center| *004*[phone number]# ||align=center| ##004# ||align=center| #004# ||align=center| *#004# ||align=center| *004#
|}

If the prefix to the forwarding command is "**" (instead of the usual "*"), then the phone number in that command is registered in the network. If after that the forwarding is deactivated using a command with a single "#", then later it will be possible to re-activate this forwarding again with a simple "*" command without a phone number in it. The forwarding will be re-activated to the number registered in the network. For example, if one uses the out-of-reach code in a forwarding command:

<code>**62*7035551212#</code>

and after that one deactivates the forwarding:

<code>#62#</code>

then later it will be possible to re-activate the out-of-reach forwarding without specifying a number:

<code>*62#</code>

After the above command, all calls made to the phone, while it is out of reach, will be forwarded to 7035551212. It is possible to activate the feature to a number other than the registered number, while still retaining the registered number for later use. For example, issuing the command:

<code>*62*7185551212#</code>

will result in calls being forwarded to 7185551212 (and '''not''' to the ''registered number'' 7035551212). However, if later a command is issued:

<code>*62#</code>

then the calls will again be forwarded to the registered number 7035551212 (and '''not''' to the number from the previous forwarding command 7185551212).