UserInteraction and its subtypes is an old way of talking about users interacting with pages. It is generally better to use [Action](https://schema.org/Action)\-based vocabulary, alongside types such as [Comment](https://schema.org/Comment).
Class Property
2 typesschema.org
An additional type for the item, typically used for adding more specific types from external vocabularies in microdata syntax. This is a relationship between something and a class that the thing is in. Typically the value is a URI-identified RDF class, and in this case corresponds to the use of rdf:type in RDF. Text values can be used sparingly, for cases where useful information can be added without their being an appropriate schema to reference. In the case of text values, the class label should follow the schema.org [style guide](https://schema.org/docs/styleguide.html).
Class Property
1 typeschema.org
A sub property of description. A short description of the item used to disambiguate from other, similar items. Information from other properties (in particular, name) may be necessary for the description to be useful for disambiguation.
Class Property
2 typesschema.org
Associates an [Event](https://schema.org/Event) with a [Schedule](https://schema.org/Schedule). There are circumstances where it is preferable to share a schedule for a series of repeating events rather than data on the individual events themselves. For example, a website or application might prefer to publish a schedule for a weekly gym class rather than provide data on every event. A schedule could be processed by applications to add forthcoming events to a calendar. An [Event](https://schema.org/Event) that is associated with a [Schedule](https://schema.org/Schedule) using this property should not have [startDate](https://schema.org/startDate) or [endDate](https://schema.org/endDate) properties. These are instead defined within the associated [Schedule](https://schema.org/Schedule), this avoids any ambiguity for clients using the data. The property might have repeated values to specify different schedules, e.g. for different months or seasons.
Class Property
3 typesschema.org
The identifier property represents any kind of identifier for any kind of [Thing](https://schema.org/Thing), such as ISBNs, GTIN codes, UUIDs etc. Schema.org provides dedicated properties for representing many of these, either as textual strings or as URL (URI) links. See [background notes](https://schema.org/docs/datamodel.html#identifierBg) for more details.
Class Property
2 typesschema.org
The language of the content or performance or used in an action. Please use one of the language codes from the [IETF BCP 47 standard](http://tools.ietf.org/html/bcp47). See also [availableLanguage](https://schema.org/availableLanguage).
Class Property
2 typesschema.org
Indicates a page (or other CreativeWork) for which this thing is the main entity being described. See [background notes](https://schema.org/docs/datamodel.html#mainEntityBackground) for details.
Class Property
1 typeschema.org
The maximum physical attendee capacity of an [Event](https://schema.org/Event) whose [eventAttendanceMode](https://schema.org/eventAttendanceMode) is [OfflineEventAttendanceMode](https://schema.org/OfflineEventAttendanceMode) (or the offline aspects, in the case of a [MixedEventAttendanceMode](https://schema.org/MixedEventAttendanceMode)).
Class Property
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The maximum virtual attendee capacity of an [Event](https://schema.org/Event) whose [eventAttendanceMode](https://schema.org/eventAttendanceMode) is [OnlineEventAttendanceMode](https://schema.org/OnlineEventAttendanceMode) (or the online aspects, in the case of a [MixedEventAttendanceMode](https://schema.org/MixedEventAttendanceMode)).
Class Property
2 typesschema.org
An offer to provide this item—for example, an offer to sell a product, rent the DVD of a movie, perform a service, or give away tickets to an event. Use [businessFunction](https://schema.org/businessFunction) to indicate the kind of transaction offered, i.e. sell, lease, etc. This property can also be used to describe a [Demand](https://schema.org/Demand). While this property is listed as expected on a number of common types, it can be used in others. In that case, using a second type, such as Product or a subtype of Product, can clarify the nature of the offer.
Class Property
2 typesschema.org
Used in conjunction with eventStatus for rescheduled or cancelled events. This property contains the previously scheduled start date. For rescheduled events, the startDate property should be used for the newly scheduled start date. In the (rare) case of an event that has been postponed and rescheduled multiple times, this field may be repeated.