Why is that certain sim cards unlock extra settings?

[cellulartalk]

Many of you may already know that the tmobile sim allows you to go deeper into the settings. I'm on a straight talk att sim on an unlocked phone iphone 5S and still don't get those extra settings. Is there a way to make them appear other than jailbreaking the phone?

More... (http://www.howardforums.com/showthread.php/1830219-Why-is-that-certain-sim-cards-unlock-extra-settings?goto=newpost)

Courtesy of WestNet Wireless
www.westnet.ca