SP.FieldMultiChoice.fillInChoice property (sp.js)
Gets or sets a value that specifies whether the field can accept values other than those specified by the Choices property.
Applies to: apps for SharePoint | SharePoint Foundation 2013 | SharePoint Server 2013
var value = SP.FieldMultiChoice.get_fillInChoice ()
var value = SP.FieldMultiChoice.set_fillInChoice ()
Return value
Type: Boolean
Setting the DisplayFormat property requires that the SP.Field.update method be called for changes to take effect in the database.