+hint
    +hint is a base class used to implement autocomplete
    functionality in the GUI. See +Hint, +Hint1, +Hint2,
    +DbHint and +Obj.
+Hint
    +Hint takes a function which is supposed to generate a list
    of matches for the argument string. See also +DbHint.
+Hint1
    +Hint1 takes an expression that produces a list of all
    values to be used. Useful if there are not too many values, for example a
    small number of constant strings or a short DB selection.
+Hint2
    +Hint2, "second hint", should be used in a field
    immediately after a +Choice- button, or after a
    +Hint1- field. It will then use the hint values of the
    preceding field. See also +Choice, +Hint1.
+HttpField
    ,"Home page" (gui '(+E/R +HttpField) '(hp : home obj) 40)