1. A method, comprising: receiving, via an element included in a user interface, a user-defined, structured input; selecting, in real time, an active input from the user-defined, structured input based at least in part on context associated with the user interface; using a processor to determine a context-sensitive rule that applies to the active input, wherein: the context-sensitive rule requires that the active input be a specific data type; and using the processor to determine the context-sensitive rule includes: setting one or more of the following: a permitted values bit or a permitted formats bit; dividing, based at least in part on the active input, inactive inputs from the user-defined, structured input into two groups: (1) those inactive inputs that affect the active input with respect to a format or content limitation and (2) those inactive inputs that do not affect the active input with respect to a format or content limitation; determining if any inactive inputs affect the active input with respect to a format or content limitation; and in the event it is determined none of the inactive inputs affect the active input with respect to a format or content limitation: determining, without taking into consideration any of the inactive inputs, if the active input is limited to certain permitted values; and determining, without taking into consideration any of the inactive inputs, if the active input is limited to certain permitted formats; and providing, in real time via the user interface, guidance associated with the active input and the context-sensitive rule, including by performing the following: displaying, in the user interface, format assistance which includes one or more of the following: (1) identification of the specific data type that satisfies the context-sensitive rule or (2) automatic configuration of the user interface so that the active input has a data type which matches the specific data type that satisfies the context-sensitive rule; and displaying, in the user interface, format validation which indicates whether the context-sensitive rule is satisfied based at least in part on a current data type of the active input.
4. The method of claim 1 , wherein providing guidance includes using one or more of the following: a still image, an audio file, a video file, a CSS style, a hyperlink, a tooltip, a help box, a dropdown box, automatic configuration of the user interface, a highlight, or an error message.