activity schema.xml

<alps>
<!--TODO: still needs some work, e.g. link objects.-->

 <description>
  ALPS descriptions of the object types and verbs defined by the
  Activity Schema draft. These may be treated as a grab bag of
  standardized names for the objects ("event", "comment", "review")
  and state transitions ("acknowledge", "dislike", "follow") typically
  found in human-facing web applications.

  The Activity Streams standard defines the object type "activity" and
  the generic "post" event; they can be found in the corresponding
  ALPS document.

  Object types ("event") can be used either as safe link relations...

<div class="object">
 <a class="url" href="http://www.example.com/events/44" rel="event">
  Birthday party
 </a>
</div>

 ...or as semantic descriptors:

<div class="event">
 Date: <span class="start">July 20, 2014</span>
</div>

  Verbs ("acknowledge") are defined as unsafe link relations:

<form action="/g555" method="POST" class="acknowledge">
 <input type="Submit" value="Acknowledge receipt of this notice."/>
</form>

  All verbs are defined as "unsafe" even though this may not be true
  for a particular application. That is, a transition like "share"
  might be unsafe or idempotent, depending on the application. [TK we
  should make our own value judgements; the Activity Schema explicitly
  mentions that "join" is idempotent but omits that kind of language
  for other things that are pretty clearly idempotent.]
 </description>

 <!--BEGIN object types.-->

 <element id="alert">
  <description>
  Any kind of significant notification.
  </description>
 </element>

 <element id="application">
  <description>
  A software application.
  </description>
 </element>

 <element id="article">
  <description>
   An article, such as a news article, knowledge base entry or similar
   construct.
  </description>
 </element>

 <element id="audio">
  <description>
   An item of audio content.
  </description>
 </element>

 <element id="badge">
  <description>
   A badge or award given to an entity.
  </description>
 </element>

 <element id="binary">
  <description>
    Objects of this type are used to carry arbitrary Base64-encoded
    binary data within an Activity Stream object. It is primarily
    intended to attach binary data to other types of objects through
    the use of the "attachments" property.
  </description>

  <element id="binary-compression" name="compression">
    <description>
      An optional token identifying a compression algorithm applied to
      the binary data prior to Base64-encoding. Possible algorithms
      are "deflate" and "gzip", respectively indicating the use of the
      compression mechanisms defined by [RFC1951] and
      [RFC1952]. Additional compression algorithms MAY be used but are
      not defined by this specification.
    </description>
  </element>

  <element id="binary-data" name="data">
    <description>
      The URL-Safe Base64-encoded representation of the binary data.
    </description>
  </element>

  <element id="binary-fileURL" name="fileURL" type="safe">
    <description>
      A link to a resource that serves the binary data as a
      representation.
    </description>
  </element>

  <element id="binary-length" name="length">
    <description>
      The total number of unencoded, uncompressed octets contained
      within the "data" field represented as a non-negative integer
      value.
    </description>
  </element>

  <element id="binary-md5" name="md5">
    <description>
      An MD5 checksum calculated over the unencoded, uncompressed
      octets contained with the "data" field.
    </description>
  </element>

  <element id="binary-mimeType" name="mimeType">
    <description>
      The MIME type of the binary data.
    </description>
  </element>

 </element>

 <element id="bookmark">
  <description>
   A pointer to a URL.
  </description>
 </element>

 <element id="collection">
  <description>
   A generic collection of objects of any type.
  </description>

  <element id="collection-itemsAfter" name="itemsAfter">
    <description>
      An [RFC3339] date-time, indicating that the collection contains
      only items published or updated after the date and time
      specified.
    </description>
  </element>

  <element id="collection-itemsBefore" name="itemsBefore">
    <description>
      An [RFC3339] date-time, indicating that the collection contains
      only items published or updated before the date and time
      specified.
    </description>
  </element>

  <element id="collection-itemsPerPage" name="itemsPerPage">
    <description>
      A non-negative integer specifying the maximum number of objects
      that will be present underneath 'links'
    </description>
  </element>

  <element id="collection-items" name="items">
    <description>
      Designates an ordered list of the items in this collection.
    </description>
  </element>

  <element id="collection-links" name="links">
    <description>
      A collection of links connecting this collection to other
      collections, each containing additional items that can be
      considered members of the collection.

      Each link should use one of the following IANA-registered link
      relations: "first", "least", "prev", "next", "current", "self".
    </description>
  </element>

  <element id="collection-startIndex" name="startIndex">
    <description>
      A non-negative integer value identifying the relative position
      within the collection of the first element contained in the
      'items' property. For instance, if there are 20 items that are
      considered to be members of a collection, but only the last 10
      of those items are serialized within the value of the items
      property, the value of startIndex would be 10.
    </description>
  </element>

 </element>

 <element id="comment">
  <description>
   A textual response to another object.
  </description>
 </element>

 <element id="device">
  <description>
   A device of any type.
  </description>
 </element>

 <element id="event">
  <description>
   An event that occurs in a certain place during a particular
   interval of time.
  </description>

  <element href="#attendedBy"/>
  <element href="#attending"/>
  <element href="#endTime"/>
  <element href="#invited"/>
  <element href="#maybeAttending"/>
  <element href="#notAttendedBy"/>
  <element href="#notAttending"/>
  <element href="#startTime"/>
 </element>

 <element id="file">
  <description>
   A document or other file with no additional machine-readable semantics.
  </description>
 </element>

 <element id="game">
  <description>
   A game or competition of any kind.
  </description>
 </element>

 <element id="group">
  <description>
   A social networking group.
  </description>
 </element>

 <element id="image">
  <description>
   A graphical image.
  </description>
 </element>

 <element id="issue">
  <description>
   Represents a report about a problem or situation that needs to be
   resolved. For instance, the issue object can be used to represent
   reports detailing software defects, or reports of acceptable use
   violations, and so forth.
  </description>

  <element id="issue-type" name="type" type="safe">
   A link to a resource that describes the type of issue.
  </element>

 </element>

 <element id="job">
  <description>
   A job or job posting.
  </description>
 </element>

 <element id="link">
  <description>
   A link to another resource.
  </description>

  <element id="link-hreflang" name="hreflang">
   <description>
     A Language Tag [RFC4646] that hints at language of the target
     resource.
   </description>
  </element>

  <element id="link-title" name="title">
   <description>
     A human-readable descriptive label for the link.
   </description>
  </element>

  <element id="link-type" name="type">
   <description>
     A hint that identifies the media type of the linked resource.
   </description>
  </element>

 </element>

 <element id="note">
  <description>
   A short-form text message.
  </description>
 </element>

 <element id="offer">
  <description>
   An offer of any kind.
  </description>
 </element>

 <element id="organization">
  <description>
   An organization of any kind.
  </description>
 </element>

 <element id="page">
  <description>
   Represents an area, typically a web page, that is representative
   of, and generally managed by a particular entity.  Such areas are
   usually dedicated to displaying descriptive information about the
   entity and showcasing recent content such as articles, photographs
   and videos.

   Most social networking applications, for example, provide
   individual users with their own dedicated "profile" pages. Several
   allow similar types of pages to be created for commercial entities,
   organizations or events.

   While the specific details of how pages are implemented, their
   characteristics and use may vary, the one unifying property is that
   they are typically "owned" by a single entity that is represented
   by the content provided by the page itself.
  </description>
 </element>

 <element id="person">
  <description>
   A user account.
  </description>
 </element>

 <element id="place">
  <description>
   A location on Earth.
  </description>
 </element>

 <element id="process">
  <description>
   Represents any form of process. For instance, a long-running task
   that is started and expected to continue operating for a period of
   time.
  </description>
 </element>

 <element id="product">
  <description>
   A commercial good or service.
  </description>
 </element>

 <element id="question">
  <description>
   A question or poll.
  </description>
 </element>

 <element id="review">
  <description>
   A primarily prose-based commentary on another object.
  </description>
 </element>

 <element id="service">
  <description>
   Something that provides a service to others.
  </description>
 </element>

 <element id="task">
  <description>
   An activity that has yet to be completed.
  </description>

  <element id="task-actor" name="actor" appears="MAY">
    <description>
      The actor that is expected to complete the task.
    </description>
  </element>

  <element id="task-by" name="by" appears="MAY">
    <description>
      An [RFC3339] timestamp specifying the date and time by which the
      task is to be completed.
    </description>
  </element>

  <element id="task-object" name="object" href="http://path/to/activitystreams.xml#object" appears="MAY">
    <description>
      The object of the task.
    </description>
  </element>

  <element id="prerequisite" cardinality="many" appears="MAY">
    <description>
     Another task which must be completed before this one.
    </description>
  </element>

  <element id="task-required" name="required" appears="MAY">
    <description>
      A boolean value indicating whether completion of the task is
      considered to be mandatory or not.
    </description>
  </element>

  <element id="supersedes" appears="MAY" cardinality="many">
    <description>
      A task superceded by this one.
    </description>
  </element>

  <element id="task-verb" name="verb" appears="MAY">
    <description>
      The verb for this task as defined for the 'verb' property
      of an Activity Streams activity.
    </description>
  </element>

 </element>

 <element id="video">
  <description>
   An item of video content.
  </description>
 </element>

 <!--BEGIN verbs.-->

 <element id="accept" type="unsafe">
  <description>
   The act of accepting an object. For instance, a person accepting an
   award, or accepting an assignment.
  </description>
 </element>

 <element id="access" type="unsafe">
  <description>
   The act of accessing the object. For instance, a person accessing a
   room, or accessing a file.
  </description>
 </element>

 <element id="acknowledge" type="unsafe">
  <description>
   Indicates that the actor has acknowledged the object. This
   effectively signals that the actor is aware of the object's
   existence.
  </description>
 </element>

 <element id="add" type="unsafe">
  <description>
   Indicates that the actor has added the object to the target. For
   instance, adding a photo to an album.
  </description>
 </element>

 <element id="agree" type="unsafe">
  <description>
   Indicates that the actor agrees with the object. For example, a
   person agreeing with an argument, or expressing agreement with a
   particular issue.
  </description>
 </element>

 <element id="append" type="unsafe">
  <description>
   Indicates that the actor has appended the object to the target. For
   instance, a person appending a new record to a database.
  </description>
 </element>

 <element id="approve" type="unsafe">
  <description>
   Indicates that the actor has approved the object. For instance, a
   manager might approve a travel request.
  </description>
 </element>

 <element id="archive" type="unsafe">
  <description>
   Indicates that the actor has archived the object.
  </description>
 </element>

 <element id="assign" type="unsafe">
  <description>
   Indicates that the actor has assigned the object to the target.
  </description>
 </element>

 <element id="at" type="unsafe">
  <description>
   Indicates that the actor is currently located at the object. For
   instance, a person being at a specific physical location.
  </description>
 </element>

 <element id="attach" type="unsafe">
  <description>
   Indicates that the actor has attached the object to the target. For
   instance, a person attaching a file to a wiki page or an email.
  </description>
 </element>

 <element id="attend" type="unsafe">
  <description>
   Indicates that the actor has attended the object. For instance, a
   person attending a meeting.
  </description>
 </element>

 <element id="author" type="unsafe">
  <description>
   Indicates that the actor has authored the object. Note that this is
   a more specific form of the verb "create".
  </description>
 </element>

 <element id="authorize" type="unsafe">
  <description>
   Indicates that the actor has authorized the object. If a target is
   specified, it means that the authorization is specifically in
   regards to the target.

   For instance, a service can authorize a person to access a given
   application; in which case the actor is the service, the object is
   the person, and the target is the application.

   In contrast, a person can authorize a request; in which case the
   actor is the person and the object is the request and there might
   be no explicit target.
  </description>
 </element>

 <element id="borrow" type="unsafe">
  <description>
   Indicates that the actor has borrowed the object. If a target is
   specified, it identifies the entity from which the object was
   borrowed. For instance, if a person borrows a book from a library,
   the person is the actor, the book is the object and the library is
   the target.
  </description>
 </element>

 <element id="build" type="unsafe">
  <description>
   Indicates that the actor has built the object. For example, if a
   person builds a model or compiles code.
  </description>
 </element>

 <element id="cancel" type="unsafe">
  <description>
   Indicates that the actor has canceled the object. For instance,
   canceling a calendar event.
  </description>
 </element>

 <element id="checkin" type="unsafe">
  <description>
   Indicates that the actor has checked-in to the object. For
   instance, a person checking-in to a Place.
  </description>
 </element>

 <element id="close" type="unsafe">
  <description>
   Indicates that the actor has closed the object. For instance, the
   object could represent a ticket being tracked in an issue
   management system.
  </description>
 </element>

 <element id="complete" type="unsafe">
  <description>
   Indicates that the actor has completed the object.
  </description>
 </element>

 <element id="confirm" type="unsafe">
  <description>
   Indicates that the actor has confirmed or agrees with the
   object. For instance, a software developer might confirm an issue
   reported against a product.
  </description>
 </element>

 <element id="consume" type="unsafe">
  <description>
   Indicates that the actor has consumed the object. The specific
   meaning is dependent largely on the object's type.  For instance,
   an actor may "consume" an audio object, indicating that the actor
   has listened to it; or an actor may "consume" a book, indicating
   that the book has been read.

   As such, the "consume" verb is a more generic form of other more
   specific verbs such as "read" and "play".
  </description>
 </element>

 <element id="create" type="unsafe">
  <description>
   Indicates that the actor has created the object.
  </description>
 </element>

 <element id="delete" type="unsafe">
  <description>
   Indicates that the actor has deleted the object. This implies, but
   does not require, the permanent destruction of the object.
  </description>
 </element>

 <element id="deliver" type="unsafe">
  <description>
   Indicates that the actor has delivered the object. For example,
   delivering a package.
  </description>
 </element>

 <element id="deny" type="unsafe">
  <description>
   Indicates that the actor has denied the object. For example, a
   manager may deny a travel request.
  </description>
 </element>

 <element id="disagree" type="unsafe">
  <description>
   Indicates that the actor disagrees with the object.
  </description>
 </element>

 <element id="dislike" type="unsafe">
  <description>
   Indicates that the actor dislikes the object. Note that the
   "dislike" verb is distinct from the "unlike" verb which assumes
   that the object had been previously "liked".
  </description>
 </element>

 <element id="experience" type="unsafe">
  <description>
   Indicates that the actor has experienced the object in some
   manner. Note that, depending on the specific object types used for
   both the actor and object, the meaning of this verb can overlap
   that of the "consume" and "play" verbs. For instance, a person
   might "experience" a movie; or "play" the movie; or "consume" the
   movie.  The "experience" verb can be considered a more generic form
   of other more specific verbs as "consume", "play", "watch",
   "listen", and "read"
  </description>
 </element>

 <element id="favorite" type="unsafe">
  <description>
   Indicates that the actor marked the object as an item of special
   interest.
  </description>
 </element>

 <element id="find" type="unsafe">
  <description>
   Indicates that the actor has found the object.
  </description>
 </element>

 <element id="flag-as-inappropriate" type="unsafe">
  <description>
   Indicates that the actor has flagged the object as being
   inappropriate for some reason. When using this verb, the "context"
   property can be used to provide additional detail about why the
   object has been flagged.
  </description>
 </element>

 <element id="follow" type="unsafe">
  <description>
   Indicates that the actor began following the activity of the
   object. In most cases, the object will be a Person, but it can
   potentially be of any type that can sensibly generate
   activity. Processors MAY ignore (silently drop) successive
   identical "follow" activities.
  </description>
 </element>

 <element id="give" type="unsafe">
  <description>
   Indicates that the actor is giving an object to the
   target. Examples include one person giving a badge object to
   another person. The object identifies the object being given. The
   target identifies the receiver.
  </description>
 </element>

 <element id="host" type="unsafe">
  <description>
   Indicates that the actor is hosting the object. As in hosting an
   event, or hosting a service.
  </description>
 </element>

 <element id="ignore" type="unsafe">
  <description>
   Indicates that the actor has ignored the object. For instance, this
   verb may be used when an actor has ignored a friend request, in
   which case the object may be the request-friend activity.
  </description>
 </element>

 <element id="insert" type="unsafe">
  <description>
   Indicates that the actor has inserted the object into the target.
  </description>
 </element>

 <element id="install" type="unsafe">
  <description>
   Indicates that the actor has installed the object, as in installing
   an application.
  </description>
 </element>

 <element id="interact" type="unsafe">
  <description>
   Indicates that the actor has interacted with the object. For
   instance, when one person interacts with another.
  </description>
 </element>

 <element id="invite" type="unsafe">
  <description>
   Indicates that the actor has invited the object, typically a
   person, to join or participate in the object described by the
   target. The target could, for instance, be an event, group or a
   service.
  </description>
 </element>

 <element id="join" type="unsafe">
  <description>
   Indicates that the actor has become a member of the object.
  </description>
 </element>

 <element id="leave" type="unsafe">
  <description>
   Indicates that the actor has left the object. For instance a Person
   leaving a Group or checking-out of a Place.
  </description>
 </element>

 <element id="like" type="unsafe">
  <description>
   Indicates that the actor marked the object as an item of special
   interest. The "like" verb is considered to be an alias of
   "favorite". The two verb are semantically identical.
  </description>
 </element>

 <element id="listen" type="unsafe">
  <description>
   Indicates that the actor has listened to the object. This is
   typically only applicable for objects representing audio content,
   such as music, an audio-book, or a radio broadcast. The "listen"
   verb is a more specific form of the "consume", "experience" and
   "play" verbs.
  </description>
 </element>

 <element id="lose" type="unsafe">
  <description>
   Indicates that the actor has lost the object. For instance, if a
   person loses a game.
  </description>
 </element>

 <element id="make-friend" type="unsafe">
  <description>
   Indicates the creation of a friendship that is reciprocated by the
   object. Since this verb implies an activity on the part of its
   object, processors MUST NOT accept activities with this verb unless
   they are able to verify through some external means that there is
   in fact a reciprocated connection. For example, a processor may
   have received a guarantee from a particular publisher that the
   publisher will only use this Verb in cases where a reciprocal
   relationship exists.
  </description>
 </element>

 <element id="open" type="unsafe">
  <description>
   Indicates that the actor has opened the object. For instance, the
   object could represent a ticket being tracked in an issue
   management system.
  </description>
 </element>

 <element id="play" type="unsafe">
  <description>
   Indicates that the actor spent some time enjoying the object. For
   example, if the object is a video this indicates that the subject
   watched all or part of the video.
  </description>
 </element>

 <element id="present" type="unsafe">
  <description>
   Indicates that the actor has presented the object. For instance,
   when a person gives a presentation at a conference.
  </description>
 </element>

 <element id="purchase" type="unsafe">
  <description>
   Indicates that the actor has purchased the object. If a target is
   specified, in indicates the entity from which the object was
   purchased.
  </description>
 </element>

 <element id="qualify" type="unsafe">
  <description>
   Indicates that the actor has qualified for the object. If a target
   is specified, it indicates the context within which the
   qualification applies.
  </description>
 </element>

 <element id="read" type="unsafe">
  <description>
   Indicates that the actor read the object.  This is typically only
   applicable for objects representing printed or written content,
   such as a book, a message or a comment. The "read" verb is a more
   specific form of the "consume", "experience" and "play" verbs.
  </description>
 </element>

 <element id="receive" type="unsafe">
  <description>
   Indicates that the actor is receiving an object. Examples include a
   person receiving a badge object. The object identifies the object
   being received.
  </description>
 </element>

 <element id="reject" type="unsafe">
  <description>
   Indicates that the actor has rejected the object.
  </description>
 </element>

 <element id="remove" type="unsafe">
  <description>
   Indicates that the actor has removed the object from the target.
  </description>
 </element>

 <element id="remove-friend" type="unsafe">
  <description>
   Indicates that the actor has removed the object from the collection
   of friends.
  </description>
 </element>

 <element id="replace" type="unsafe">
  <description>
   Indicates that the actor has replaced the target with the object.
  </description>
 </element>

 <element id="request" type="unsafe">
  <description>
   Indicates that the actor has requested the object. If a target is
   specified, it indicates the entity from which the object is being
   requested.
  </description>
 </element>

 <element id="request-friend" type="unsafe">
  <description>
   Indicates the creation of a friendship that has not yet been
   reciprocated by the object.
  </description>
 </element>

 <element id="resolve" type="unsafe">
  <description>
   Indicates that the actor has resolved the object. For instance, the
   object could represent a ticket being tracked in an issue
   management system.
  </description>
 </element>

 <element id="retract" type="unsafe">
  <description>
   Indicates that the actor has retracted the object. For instance, if
   an actor wishes to retract a previously published activity, the
   object would be the previously published activity that is being
   retracted.
  </description>
 </element>

 <element id="return" type="unsafe">
  <description>
   Indicates that the actor has returned the object. If a target is
   specified, it indicates the entity to which the object was
   returned.
  </description>
 </element>

 <element id="rsvp-maybe" type="unsafe">
  <description>
   The "possible RSVP" verb indicates that the actor has made a
   possible RSVP for the object. This specification only defines the
   meaning of this verb when its object is an event, though
   implementors SHOULD be prepared to handle other object types as
   meaning MAY be provided by extension specifications. The use of
   this verb is only appropriate when the RSVP was created by an
   explicit action by the actor. It is not appropriate to use this
   verb when a user has been added as an attendee by an event
   organiser or administrator.
  </description>
 </element>

 <element id="rsvp-no" type="unsafe">
  <description>
   The "negative RSVP" verb indicates that the actor has made a
   negative RSVP for the object. This specification only defines the
   meaning of this verb when its object is an event, though
   implementors SHOULD be prepared to handle other object types as
   meaning MAY be provided by extension specifications. The use of
   this verb is only appropriate when the RSVP was created by an
   explicit action by the actor. It is not appropriate to use this
   verb when a user has been added as an attendee by an event
   organiser or administrator.
  </description>
 </element>

 <element id="rsvp-yes" type="unsafe">
  <description>
   The "positive RSVP" verb indicates that the actor has made a
   positive RSVP for an object. This specification only defines the
   meaning of this verb when its object is an event, though
   implementors SHOULD be prepared to handle other object types as
   meaning MAY be provided by extension specifications. The use of
   this verb is only appropriate when the RSVP was created by an
   explicit action by the actor. It is not appropriate to use this
   verb when a user has been added as an attendee by an event
   organiser or administrator.
  </description>
 </element>

 <element id="satisfy" type="unsafe">
  <description>
   Indicates that the actor has satisfied the object. If a target is
   specified, it indicate the context within which the object was
   satisfied. For instance, if a person satisfies the requirements for
   a particular challenge, the person is the actor; the requirement is
   the object; and the challenge is the target.
  </description>
 </element>

 <element id="save" type="unsafe">
  <description>
   Indicates that the actor has called out the object as being of
   interest primarily to him- or herself. Though this action MAY be
   shared publicly, the implication is that the object has been saved
   primarily for the actor's own benefit rather than to show it to
   others as would be indicated by the "share" verb.
  </description>
 </element>

 <element id="schedule" type="unsafe">
  <description>
   Indicates that the actor has scheduled the object. For instance,
   scheduling a meeting.
  </description>
 </element>

 <element id="search" type="unsafe">
  <description>
   Indicates that the actor is or has searched for the object. If a
   target is specified, it indicates the context within which the
   search is or has been conducted.
  </description>
 </element>

 <element id="sell" type="unsafe">
  <description>
   Indicates that the actor has sold the object. If a target is
   specified, it indicates the entity to which the object was sold.
  </description>
 </element>

 <element id="send" type="unsafe">
  <description>
   Indicates that the actor has sent the object. If a target is
   specified, it indicates the entity to which the object was sent.
  </description>
 </element>

 <element id="share" type="unsafe">
  <description>
   Indicates that the actor has called out the object to readers. In
   most cases, the actor did not create the object being shared, but
   is instead drawing attention to it.
  </description>
 </element>

 <element id="sponsor" type="unsafe">
  <description>
   Indicates that the actor has sponsored the object. If a target is
   specified, it indicates the context within which the sponsorship is
   offered. For instance, a company can sponsor an event; or an
   individual can sponsor a project; etc.
  </description>
 </element>

 <element id="start" type="unsafe">
  <description>
   Indicates that the actor has started the object. For instance, when
   a person starts a project.
  </description>
 </element>

 <element id="stop-following" type="unsafe">
  <description>
   Indicates that the actor has stopped following the object.
  </description>
 </element>

 <element id="submit" type="unsafe">
  <description>
   Indicates that the actor has submitted the object. If a target is
   specified, it indicates the entity to which the object was
   submitted.
  </description>
 </element>

 <element id="tag" type="unsafe">
  <description>
   Indicates that the actor has identified the presence of a target
   inside another object. For example, the actor may have specified
   that a particular user appears in a photo. The target of the "tag"
   verb gives the object in which the tag has been added. For example,
   if a user appears in a photo, the object is the user and the target
   is the photo.
  </description>
 </element>

 <element id="terminate" type="unsafe">
  <description>
   Indicates that the actor has terminated the object.
  </description>
 </element>

 <element id="tie" type="unsafe">
  <description>
   Indicates that the actor has neither won or lost the object. This
   verb is generally only applicable when the object represents some
   form of competition, such as a game.
  </description>
 </element>

 <element id="unfavorite" type="unsafe">
  <description>
   Indicates that the actor has removed the object from the collection
   of favorited items.
  </description>
 </element>

 <element id="unlike" type="unsafe">
  <description>
   Indicates that the actor has removed the object from the collection
   of liked items.
  </description>
 </element>

 <element id="unsatisfy" type="unsafe">
  <description>
   Indicates that the actor has not satisfied the object. If a target
   is specified, it indicates the context within which the object was
   not satisfied. For instance, if a person fails to satisfy the
   requirements of some particular challenge, the person is the actor;
   the requirement is the object and the challenge is the target.
  </description>
 </element>

 <element id="unsave" type="unsafe">
  <description>
   Indicates that the actor has removed the object from the collection
   of saved items.
  </description>
 </element>

 <element id="unshare" type="unsafe">
  <description>
   Indicates that the actor is no longer sharing the object. If a
   target is specified, it indicates the entity with whom the object
   is no longer being shared.
  </description>
 </element>

 <element id="update" type="unsafe">
  <description>
   The "update" verb indicates that the actor has modified the
   object. Implementors SHOULD use verbs such as "post" where the
   actor is adding new items to a collection or similar. Update is
   reserved for modifications to existing object or data such as
   changing a user's profile information.
  </description>
 </element>

 <element id="use" type="unsafe">
  <description>
   Indicates that the actor has used the object in some manner.
  </description>
 </element>

 <element id="watch" type="unsafe">
  <description>
   Indicates that the actor has watched the object. This verb is
   typically applicable only when the object represents dynamic,
   visible content such as a movie, a television show or a public
   performance. This verb is a more specific form of the verbs
   "experience", "play" and "consume".
  </description>
 </element>

 <element id="win" type="unsafe">
  <description>
   Indicates that the actor has won the object. This verb is typically
   applicable only when the object represents some form of
   competition, such as a game.
  </description>
 </element>

 <!--BEGIN Activity Schema's extensions to the "object" descriptor-->

 <element id="context">
  <description>
   An object that provides information about why an activity occurred,
   by describing the context within which it occurred.
  </description>
 </element>

 <element id="result">
  <description>
   The result of an activity.
  </description>
 </element>

<!--BEGIN Activity Schema extensions that can apply to either the
     "activity" or the "object" descriptor.-->

<element id="dc">
 <description>
  Related Dublin Core Metadata (http://dublincore.org)
 </description>
</element>

<element id="endTime">
 <description>
  A timestamp indicating the date and time at which the activity ended.
 </description>
</element>

<element id="geojson">
 <description>
  GeoJSON Metadata related to the object (http://www.geojson.org/geojson-spec.html)
 </description>
</element>

<element id="ld">
 <description>
  JSON-LD Metadata related to the object (http://json-ld.org)
 </description>
</element>

<element id="links">
 <description>
  Links associated with the object.
 </description>
</element>

<element id="location">
 <description>
  The location at which an activity occured.
 </description>

 <element id="position">
  <description>
   The latitude, longitude and altitude of the place as a point on Earth.
  </description>
  <element>
   <element id="altitude">
    <description>
      The elevation of this point relative to the Earth, in meters
      above or below mean sea level. (e.g. 8848.00, -86.00).
    </description>
   </element>

   <element id="latitude">
    <description>
      The latitude of this point on Earth according to the WGS-84
      coordinate reference system in decimal degrees (e.g. 27.9881,
      -3.12676).
    </description>
   </element>

   <element id="longitude">
    <description>
      The longitude of this point on Earth according to the WGS-84
      coordinate reference system in decimal degrees (e.g. 86.9253,
      -134.4323).
    </description>
   </element>
  </element>

  <element id="address">
   <description>
     A physical address.
   </description>

   <element id="formatted">
     <description>
       The full mailing address formatted for display or use with a
       mailing label.
     </description>
   </element>

   <element id="streetAddress">
     <description>
       The street address including house number, street name,
       P.O. Box, and extended multi-line address information.
     </description>
   </element>

   <element id="locality">
     <description>
       The city or locality.
     </description>
   </element>

   <element id="region">
     <description>
       The state or region.
     </description>
   </element>

   <element id="postalCode">
     <description>
       The ZIP or postal code.
     </description>
   </element>

   <element id="country">
     <description>
       The country name component.
     </description>
   </element>
 </element>
</element>

<element id="mood">
 <description>
  A human-readable keyword or short phrase describing the mood of the
  actor at the time the activity was performed.
 </description>

 <element id="mood-displayName" name="displayName"
          appears="MUST">
  <description>
   The natural-language, human-readable and plain-text keyword or
   phrase describing the mood. HTML markup MUST NOT be included
  </description>
 </element>

 <element id="mood-image" name="image" appears="MAY"
          href="http://path/to/activitystreams.xml#media-link">
  <description>
   An image that provides a visual representation of the mood.
  </description>
 </element>

</element>

<element id="odata">
 <description>
  Related OData metadata (http://www.odata.org)
 </description>
</element>

<element id="opengraph">
 <description>
  Related OpenGraph metadata
  (http://developers.facebook.com/docs/opengraph)
 </description>
</element>

<element id="rating">
 <description>
  A rating given as a number between 1.0 and 5.0 inclusive with one
  decimal place of precision.
 </description>
</element>

<element id="schema_org">
 <description>
  Related Schema.org metadata (http://schema.org)
 </description>
</element>

<element id="source">
 <description>
  The original source of an activity.
 </description>
</element>

<element id="startTime">
 <description>
  An [RFC3339] timestamp indicating the date and time at which the
  activity was started.
 </description>
</element>

<element id="tags">
 <description>
  A list of objects that have been associated with a particular object
  using the tag verb.
 </description>
</element>

<!--These elements are defined as aspects of 'event' in Activity
     Schema, and as general aspects of 'object' in Responses. I'm
     defining them here, so that they can be referenced by the
     definition of 'event', and not defining them in the ALPS version
     of Responses.-->

  <element id="attendedBy" cardinality="many">
    <description>
      An actor that attended an event.
    </description>
  </element>

  <element id="attending" cardinality="many">
    <description>
      An actor who responded to an event using the rsvp-yes verb.
    </description>
  </element>

  <element id="invited" cardinality="many">
    <description>
      An actor that has been invited to an event, invited to join a group, etc.
    </description>
  </element>

  <element id="maybeAttending" cardinality="many">
    <description>
      An actor that responded to an event using the rsvp-maybe verb.
    </description>
  </element>

  <element id="notAttendedBy" cardinality="many">
    <description>
      An actor that did not attend an event.
    </description>
  </element>

  <element id="notAttending" cardinality="many">
    <description>
      An actor that has responded to an event using the "rsvp-no" verb.
    </description>
  </element>

</alps>