Not sure if it was the latest update or not, but I just noticed this error popping up. When I deactivate W3 Total Cache, it goes away. I have tried uninstalling and reinstalling the plugin with same results. I have searched and found no fix, only descriptions of the error.
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A quotation. Often but not necessarily from some written work, attributable to a real world author and – if associated with a fictional character – to any fictional Person. Use isBasedOn to link to source/origin. The recordedIn property can be used to reference a Quotation from an Event.
Property Expected Type Description Properties from Quotation
The (e.g. fictional) character, Person or Organization to whom the quotation is attributed within the containing CreativeWork. Properties from CreativeWork
Thing The subject matter of the content.
Inverse property: subjectOf.
Text The human sensory perceptual system or cognitive faculty through which a person may process or perceive information. Expected values include: auditory, tactile, textual, visual, colorDependent, chartOnVisual, chemOnVisual, diagramOnVisual, mathOnVisual, musicOnVisual, textOnVisual.
Text A list of single or combined accessModes that are sufficient to understand all the intellectual content of a resource. Expected values include: auditory, tactile, textual, visual.
Text Indicates that the resource is compatible with the referenced accessibility API (WebSchemas wiki lists possible values).
Text Identifies input methods that are sufficient to fully control the described resource (WebSchemas wiki lists possible values).
Text Content features of the resource, such as accessible media, alternatives and supported enhancements for accessibility (WebSchemas wiki lists possible values).
Text A characteristic of the described resource that is physiologically dangerous to some users. Related to WCAG 2.0 guideline 2.3 (WebSchemas wiki lists possible values).
Text A human-readable summary of specific accessibility features or deficiencies, consistent with the other accessibility metadata but expressing subtleties such as “short descriptions are present but long descriptions will be needed for non-visual users” or “short descriptions are present and no long descriptions are needed.”
Person Specifies the Person that is legally accountable for the CreativeWork.
AggregateRating The overall rating, based on a collection of reviews or ratings, of the item.
Text A secondary title of the CreativeWork.
MediaObject A media object that encodes this CreativeWork. This property is a synonym for encoding.
Audience An intended audience, i.e. a group for whom something was created. Supersedes serviceAudience.
An embedded audio object.
The author of this content or rating. Please note that author is special in that HTML 5 provides a special mechanism for indicating authorship via the rel tag. That is equivalent to this and may be used interchangeably.
Text An award won by or for this item. Supersedes awards.
Person Fictional person connected with a creative work.
A citation or reference to another creative work, such as another publication, web page, scholarly article, etc.
Comment Comments, typically from users.
Integer The number of comments this CreativeWork (e.g. Article, Question or Answer) has received. This is most applicable to works published in Web sites with commenting system; additional comments may exist elsewhere.
Place The location depicted or described in the content. For example, the location in a photograph or painting.
Official rating of a piece of content—for example,’MPAA PG-13′.
DateTime The specific time described by a creative work, for works (e.g. articles, video objects etc.) that emphasise a particular moment within an Event.
A secondary contributor to the CreativeWork or Event.
The party holding the legal copyright to the CreativeWork.
Number The year during which the claimed copyright for the CreativeWork was first asserted.
Indicates a correction to a CreativeWork, either via a CorrectionComment, textually or in another document.
The creator/author of this CreativeWork. This is the same as the Author property for CreativeWork.
The date on which the CreativeWork was created or the item was added to a DataFeed.
The date on which the CreativeWork was most recently modified or when the item’s entry was modified within a DataFeed.
Date Date of first broadcast/publication.
URL A link to the page containing the comments of the CreativeWork.
Person Specifies the Person who edited the CreativeWork.
AlignmentObject An alignment to an established educational framework.
Text The purpose of a work in the context of education; for example, ‘assignment’, ‘group work’.
MediaObject A media object that encodes this CreativeWork. This property is a synonym for associatedMedia. Supersedes encodings.
Inverse property: encodesCreativeWork.
Media type typically expressed using a MIME format (see IANA siteand MDN reference) e.g. application/zip for a SoftwareApplication binary, audio/mpeg for .mp3 etc.).
Unregistered or niche encoding and file formats can be indicated instead via the most appropriate URL, e.g. defining Web page or a Wikipedia/Wikidata entry. Supersedes fileFormat.
CreativeWork A creative work that this work is an example/instance/realization/derivation of.
Inverse property: workExample.
Date Date the content expires and is no longer useful or available. For example a VideoObject or NewsArticle whose availability or relevance is time-limited, or a ClaimReview fact check whose publisher wants to indicate that it may no longer be relevant (or helpful to highlight) after some date.
A person or organization that supports (sponsors) something through some kind of financial contribution.
Genre of the creative work, broadcast channel or group.
CreativeWork Indicates an item or CreativeWork that is part of this item, or CreativeWork (in some sense).
Inverse property: isPartOf.
Text Headline of the article.
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. See also availableLanguage. Supersedes language.
InteractionCounter The number of interactions for the CreativeWork using the WebSite or SoftwareApplication. The most specific child type of InteractionCounter should be used. Supersedes interactionCount.
Text The predominant mode of learning supported by the learning resource. Acceptable values are ‘active’, ‘expositive’, or ‘mixed’.
Boolean A flag to signal that the item, event, or place is accessible for free. Supersedes free.
A resource that was used in the creation of this resource. This term can be repeated for multiple sources. For example, http://example.com/great-multiplication-intro.html. Supersedes isBasedOnUrl.
Boolean Indicates whether this content is family friendly.
CreativeWork Indicates an item or CreativeWork that this item, or CreativeWork (in some sense), is part of.
Inverse property: hasPart.
Text Keywords or tags used to describe this content. Multiple entries in a keywords list are typically delimited by commas.
Text The predominant type or kind characterizing the learning resource. For example, ‘presentation’, ‘handout’.
A license document that applies to this content, typically indicated by URL.
Place The location where the CreativeWork was created, which may not be the same as the location depicted in the CreativeWork.
Thing Indicates the primary entity described in some page or other CreativeWork.
Inverse property: mainEntityOfPage.
A material that something is made from, e.g. leather, wool, cotton, paper.
The quantity of the materials being described or an expression of the physical space they occupy.
Thing Indicates that the CreativeWork contains a reference to, but is not necessarily about a concept.
Offer 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.
The position of an item in a series or sequence of items.
The person or organization who produced the work (e.g. music album, movie, tv/radio series etc.).
The service provider, service operator, or service performer; the goods producer. Another party (a seller) may offer those services or goods on behalf of the provider. A provider may also serve as the seller. Supersedes carrier.
PublicationEvent A publication event associated with the item.
The publisher of the creative work.
Organization The publishing division which published the comic.
The publishingPrinciples property indicates (typically via URL) a document describing the editorial principles of an Organization(or individual e.g. a Person writing a blog) that relate to their activities as a publisher, e.g. ethics or diversity policies. When applied to a CreativeWork (e.g. NewsArticle) the principles are those of the party primarily responsible for the creation of the CreativeWork.
While such policies are most typically expressed in natural language, sometimes related information (e.g. indicating a funder) can be expressed using schema.org terminology.
Event The Event where the CreativeWork was recorded. The CreativeWork may capture all or part of the event.
Inverse property: recordedIn.
PublicationEvent The place and time the release was issued, expressed as a PublicationEvent.
Review A review of the item. Supersedes reviews.
Indicates (by URL or string) a particular version of a schema used in some CreativeWork. For example, a document could declare a schemaVersion using an URL such as http://schema.org/version/2.0/ if precise indication of schema version was required by some application.
Date Indicates the date on which the current structured data was generated / published. Typically used alongside sdPublisher
A license document that applies to this structured data, typically indicated by URL.
Indicates the party responsible for generating and publishing the current structured data markup, typically in cases where the structured data is derived automatically from existing published content but published on a different site. For example, student projects and open data initiatives often re-publish existing content with more explicitly structured metadata. The sdPublisherproperty helps make such practices more explicit.
Organization The Organization on whose behalf the creator was working.
Place The “spatial” property can be used in cases when more specific properties (e.g. locationCreated, spatialCoverage, contentLocation) are not known to be appropriate.
Place The spatialCoverage of a CreativeWork indicates the place(s) which are the focus of the content. It is a subproperty of contentLocation intended primarily for more technical and detailed materials. For example with a Dataset, it indicates areas that the dataset describes: a dataset of New York weather would have spatialCoverage which was the place: the state of New York.
A person or organization that supports a thing through a pledge, promise, or financial contribution. e.g. a sponsor of a Medical Study or a corporate sponsor of an event.
The “temporal” property can be used in cases where more specific properties (e.g. temporalCoverage, dateCreated, dateModified, datePublished) are not known to be appropriate.
The temporalCoverage of a CreativeWork indicates the period that the content applies to, i.e. that it describes, either as a DateTime or as a textual string indicating a time period in ISO 8601 time interval format. In the case of a Dataset it will typically indicate the relevant time period in a precise notation (e.g. for a 2011 census dataset, the year 2011 would be written “2011/2012”). Other forms of content e.g. ScholarlyArticle, Book, TVSeries or TVEpisode may indicate their temporalCoverage in broader terms – textually or via well-known URL. Written works such as books may sometimes have precise temporal coverage too, e.g. a work set in 1939 – 1945 can be indicated in ISO 8601 interval format format via “1939/1945”.
Open-ended date ranges can be written with “..” in place of the end date. For example, “2015-11/..” indicates a range beginning in November 2015 and with no specified final date. This is tentative and might be updated in future when ISO 8601 is officially updated. Supersedes datasetTimeInterval.
Text The textual content of this CreativeWork.
URL A thumbnail image relevant to the Thing.
Duration Approximate or typical time it takes to work with or through this learning resource for the typical intended target audience, e.g. ‘PT30M’, ‘PT1H25M’.
CreativeWork The work that this work has been translated from. e.g. 物种起源 is a translationOf “On the Origin of Species”
Inverse property: workTranslation.
Organization or person who adapts a creative work to different languages, regional differences and technical requirements of a target market, or that translates during some event.
Text The typical expected age range, e.g. ‘7-9’, ’11-‘.
The version of the CreativeWork embodied by a specified resource.
An embedded video object.
CreativeWork Example/instance/realization/derivation of the concept of this creative work. eg. The paperback edition, first edition, or eBook.
Inverse property: exampleOfWork.
CreativeWork A work that is a translation of the content of this work. e.g. 西遊記 has an English workTranslation “Journey to the West”,a German workTranslation “Monkeys Pilgerfahrt” and a Vietnamese translation Tây du ký bình khảo.
Inverse property: translationOfWork.
Properties from Thing
URL 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. In RDFa syntax, it is better to use the native RDFa syntax – the ‘typeof’ attribute – for multiple types. Schema.org tools may have only weaker understanding of extra types, in particular those defined externally.
Text An alias for the item.
Text A description of the item.
Text 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.
The identifier property represents any kind of identifier for any kind of 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 for more details.
An image of the item. This can be a URL or a fully described ImageObject.
Indicates a page (or other CreativeWork) for which this thing is the main entity being described. See background notes for details.
Inverse property: mainEntity.
Text The name of the item.
Action Indicates a potential Action, which describes an idealized action in which this thing would play an ‘object’ role.
URL URL of a reference Web page that unambiguously indicates the item’s identity. E.g. the URL of the item’s Wikipedia page, Wikidata entry, or official website.
A CreativeWork or Event about this Thing..
Inverse property: about.
URL URL of the item.
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