14. One or more computer-readable media storing computer-executable instructions that, when executed, cause one or more processors to perform acts comprising: providing a first user input mode that restricts an input in a text field to a first specified set of characters or that causes display of an input in the text field in a first specified manner; before submittal by a user of an input provided in the text field, transitioning from the first user input mode to a second user input mode; and providing the second user input mode, the second user input mode restricting an input in the text field to a second specified set of characters that differs from the first specified set or causing display of an input in the text field in a second specified manner that differs from the first specified manner.
14. One or more computer-readable media storing computer-executable instructions that, when executed, cause one or more processors to perform acts comprising: providing a first user input mode that restricts an input in a text field to a first specified set of characters or that causes display of an input in the text field in a first specified manner; before submittal by a user of an input provided in the text field, transitioning from the first user input mode to a second user input mode; and providing the second user input mode, the second user input mode restricting an input in the text field to a second specified set of characters that differs from the first specified set or causing display of an input in the text field in a second specified manner that differs from the first specified manner. 17. One or more computer-readable media recited in claim 14 , wherein: the first user input mode causes display of an input in the first specified manner, the first specified manner comprising displaying the input with a first set of font characteristics; and the second user input mode causes display of an input in the second specified manner, the second specified manner comprising displaying the input with a second set of font characteristics that differs from the first set of font characteristics.