EpubCCMensajes de EPUBCheck explicados
EPUBCheck informa cada problema en un EPUB como un código como RSC-005 u OPF-014 con una severidad. Esta referencia enumera todos los mensajes de 246 de EPUBCheck 5.4.0 con su texto oficial y explica causas y soluciones para 188 de ellos.
Actualizado:
Severidades
- Error fatal
- EPUBCheck no pudo continuar revisando esta parte del EPUB. El archivo no es válido.
- Error
- El EPUB rompe una regla de la especificación y es inválido. Las tiendas y el envío a Kindle pueden rechazarlo, y EPUBCheck sale con estado 1.
- Advertencia
- El EPUB sigue siendo válido, pero es probable que algo cause problemas en algunas aplicaciones de lectura. EPUBCheck sale con 0 a menos que pases --failonwarnings.
- Uso
- Informativo solo y oculto por defecto: aparece cuando EPUBCheck se ejecuta con -u (--usage). No hace que el EPUB sea inválido.
- Información
- Informativo solo. No hace que el EPUB sea inválido.
- Suprimido
- EPUBCheck no reporta este mensaje por defecto. Solo aparece si un archivo de mensajes personalizados (-c) cambia su gravedad.
PKG: Paquete y contenedor ZIP
El EPUB archivo en sí: el archivo ZIP, el archivo mimetype, nombres de archivos y extensiones.
| Código | Severidad por defecto | Mensaje |
|---|---|---|
PKG-001 | Advertencia | Validating the EPUB against version … but detected version …. |
PKG-003 | Error | Unable to read EPUB file header. This is likely a corrupted EPUB file. |
PKG-004 | Error fatal | Corrupted EPUB ZIP header. |
PKG-005 | Error | The mimetype file has an extra field of length …. The use of the extra field feature of the ZIP format is not permitted for the mimetype file. |
PKG-006 | Error | Mimetype file entry is missing or is not the first file in the archive. |
PKG-007 | Error | The content of the mimetype file must be the string "application/epub+zip"… |
PKG-008 | Error fatal | Unable to read file "…". |
PKG-009 | Error | The file name "…" contains characters that are not allowed in OCF file names: …. |
PKG-010 | Advertencia | The file name "…" contains spaces, which may create interoperability issues with older reading systems. |
PKG-011 | Error | The file name "…" is not allowed to end with ".". |
PKG-012 | Uso | The file name "…" contains non-ASCII characters, which might create interoperability issues with older reading systems. |
PKG-013 | Error | The EPUB file includes multiple OPS renditions. |
PKG-014 | Advertencia | The EPUB contains empty directory "…". |
PKG-015 | Error fatal | Unable to read EPUB contents: … |
PKG-016 | Advertencia | Use only lowercase characters for the EPUB file extension for maximum compatibility. |
PKG-017 | Advertencia | Uncommon EPUB file extension. |
PKG-018 | Error fatal | The EPUB file could not be found. |
PKG-020 | Error | OPF file "…" could not be found. |
PKG-021 | Error | Corrupted image file encountered. |
PKG-022 | Advertencia | Wrong file extension for image. The image is a "…" file but has the file extension "…". |
PKG-023 | Uso | Validating the EPUB against version 2.0, default validation profile will be used. |
PKG-024 | Uso | Uncommon EPUB file extension. |
PKG-025 | Error | Publication resource must not be located in the META-INF directory |
PKG-026 | Error | Obfuscated resource must be a Font Core Media Type (was declared as "…" in "…"). |
PKG-027 | Error fatal | Could not extract EPUB ZIP content, probably due to file names not encoded in UTF-8. |
RSC: Recursos y referencias
Archivos y enlaces entre ellos: archivos faltantes, referencias rotas, URLs, codificaciones y análisis XML.
| Código | Severidad por defecto | Mensaje |
|---|---|---|
RSC-001 | Error | File "…" could not be found. |
RSC-002 | Error fatal | Required META-INF/container.xml resource could not be found. |
RSC-003 | Error | No rootfile tag with media type "application/oebps-package+xml" was found in the container. |
RSC-004 | Información | File "…" is encrypted, its content will not be checked. |
RSC-005 | Error | Error while parsing file: … |
RSC-006 | Error | Remote resource reference is not allowed in this context; resource "…" must be located in the EPUB container. |
RSC-006b | Uso | Resource "…" is located outside the EPUB Container; please check the resource is retrieved in scripted content. |
RSC-007 | Error | Referenced resource "…" could not be found in the EPUB. |
RSC-007w | Advertencia | Referenced resource "…" could not be found in the EPUB. |
RSC-008 | Error | Referenced resource "…" is not declared in the OPF manifest. |
RSC-009 | Advertencia | A non-SVG image resource should not be defined with a fragment identifier. |
RSC-010 | Error | Reference to non-standard resource type found. |
RSC-011 | Error | Found a reference to a resource that is not a spine item. |
RSC-012 | Error | Fragment identifier is not defined. |
RSC-013 | Uso | Fragment identifier is used in a reference to a stylesheet resource. |
RSC-014 | Uso | Fragment identifier defines an incompatible resource type. |
RSC-015 | Uso | A fragment identifier is required for svg use tag references. |
RSC-016 | Error fatal | Fatal Error while parsing file: … |
RSC-017 | Advertencia | Warning while parsing file: … |
RSC-019 | Advertencia | EPUBs with Multiple Renditions should contain a META-INF/metadata.xml file. |
RSC-020 | Error | "…" is not a valid URL (…) |
RSC-021 | Error | A Search Key Map Document must point to Content Documents ("…" was not found in the spine). |
RSC-022 | Información | Cannot check image details (requires Java version 7 or higher). |
RSC-024 | Uso | Informative parsing warning: … |
RSC-025 | Uso | Informative parsing error: … |
RSC-026 | Error | URL "…" leaks outside the container (it is not a valid-relative-ocf-URL-with-fragment string) |
RSC-027 | Advertencia | XML document is encoded in UTF-16. It should be encoded in UTF-8 instead. |
RSC-028 | Error | XML documents must be encoded in UTF-8, but … was detected. |
RSC-029 | Error | Data URL is not allowed in this context. |
RSC-030 | Error | File URLs are not allowed in EPUB, but found "…". |
RSC-031 | Advertencia | Remote resource references should use HTTPS, but found "…". |
RSC-032 | Error | Fallback must be provided for foreign resources, but found none for resource "…" of type "…". |
RSC-033 | Error | Relative URL strings must not have a query component, but found one in "…". |
RSC-034 | Error | Scripts must have a JavaScript media type. |
RSC-035 | Uso | "…" is a legacy media type for JavaScript. Consider using 'text/javascript' instead. |
RSC-036 | Uso | … |
OPF: Documento de paquete (OPF)
El documento del paquete: metadatos, manifiesto, spine, propiedades y sustituciones.
| Código | Severidad por defecto | Mensaje |
|---|---|---|
OPF-001 | Error | There was an error when parsing the EPUB version: …. |
OPF-002 | Error fatal | The OPF file "…" was not found in the EPUB. |
OPF-003 | Uso | Item "…" exists in the EPUB, but is not declared in the OPF manifest. |
OPF-004 | Advertencia | Invalid prefix declaration: leading or trailing whitespace is not allowed. |
OPF-004a | Error | Invalid prefix declaration: found empty prefix. |
OPF-004b | Error | Invalid prefix "…": must be a valid non-colonized name (aka "NCName"). |
OPF-004c | Error | Invalid prefix declaration: prefix "…" must be immediately followed by a colon character (":"). |
OPF-004d | Error | Invalid prefix declaration: prefix "…" must be separated by its URI with a space. |
OPF-004e | Advertencia | Invalid prefix declaration: found illegal whitespace between prefix and URI. |
OPF-004f | Advertencia | Invalid prefix declaration: found illegal whitespace between prefix mappings. |
OPF-005 | Error | Invalid prefix declaration: URI for prefix "…" doesn’t exist. |
OPF-006 | Error | Invalid prefix declaration: URI "…" is not a valid URI. |
OPF-007 | Advertencia | Re-declaration of reserved prefix "…". |
OPF-007a | Error | Invalid prefix mapping: prefix "_" must not be declared. |
OPF-007b | Error | Invalid prefix mapping: default vocabulary "…" must not be re-declared. |
OPF-007c | Error | Invalid prefix mapping: a prefix to the Dublin Core /elements/1.1/ namespace must not be declared |
OPF-010 | Error | Error resolving reference: "…". |
OPF-011 | Error | itemref can’t have both page-spread-right and page-spread-left properties. |
OPF-012 | Error | Item property "…" is not defined for media type "…". |
OPF-013 | Advertencia | Resource "…" is declared with MIME type "…" in content, but has MIME type "…" in the package document. |
OPF-014 | Error | The property "…" should be declared in the OPF file. |
OPF-015 | Error | The property "…" should not be declared in the OPF file. |
OPF-016 | Error | The element "rootfile" is missing its required attribute "full-path". |
OPF-017 | Error | The attribute "full-path" on element "rootfile" must not be empty. |
OPF-018 | Advertencia | The "remote-resources" property was declared in the Package Document, but no reference to remote resources has been found. |
OPF-018b | Uso | The "remote-resources" property was declared in the Package Document, but no reference to remote resources has been found; please check scripted content to make sure the property is legit. |
OPF-021 | Advertencia | Use of non-registered URI scheme type in href: "…". |
OPF-025 | Error | Property value list "…" is not allowed, only one value must be specified. |
OPF-026 | Error | Found malformed property value: "…". |
OPF-027 | Error | Undefined property: "…". |
OPF-028 | Error | Undeclared prefix: "…". |
OPF-029 | Error | The file "…" does not appear to match the media type …, as specified in the OPF file. |
OPF-030 | Error | The unique-identifier "…" was not found. |
OPF-031 | Error | File listed in reference element in guide was not declared in OPF manifest: …. |
OPF-032 | Error | Guide references "…" which is not a valid "OPS Content Document". |
OPF-033 | Error | The spine contains no linear resources. |
OPF-034 | Error | The spine contains multiple references to the manifest item with id "…". |
OPF-035 | Advertencia | Media type "text/html" is not appropriate for XHTML/OPS. |
OPF-036 | Uso | Video type "…" might not be supported by reading systems |
OPF-037 | Advertencia | Found deprecated media-type "…". |
OPF-038 | Advertencia | Media type "…" is not appropriate for an OEBPS 1.2 context; Use "text/x-oeb1-document" instead. |
OPF-039 | Advertencia | Media-type "…" is not appropriate in an OEBPS 1.2 context. Use "text/x-oeb1-css" instead. |
OPF-040 | Error | Fallback item with id "…" could not be found. |
OPF-041 | Error | Fallback-style item with id "…" could not be found. |
OPF-042 | Error | "…" is not a permissible spine media-type. |
OPF-043 | Error | Spine item with non-standard media-type "…" has no fallback. |
OPF-044 | Error | Spine item with non-standard media-type "…" has no EPUB content document fallback. |
OPF-045 | Error | Encountered circular reference in fallback chain. |
OPF-047 | Uso | OPF file is using OEBPS 1.2 syntax allowing backwards compatibility. |
OPF-048 | Error | Package tag is missing its required unique-identifier attribute and value. |
OPF-049 | Error | Item id "…" was not found in the manifest. |
OPF-050 | Error | TOC attribute references resource with non-NCX mime type; "application/x-dtbncx+xml" is expected. |
OPF-051 | Suprimido | Image dimensions exceed recommended size. |
OPF-052 | Error | Role value "…" is not valid. |
OPF-053 | Advertencia | Date value "…" does not follow recommended syntax as per http://www.w3.org/TR/NOTE-datetime:…. |
OPF-054 | Error | Date value "…" is not valid as per http://www.w3.org/TR/NOTE-datetime:…. |
OPF-055 | Advertencia | … tag is empty. |
OPF-057 | Suprimido | Image file length exceeds recommended size. |
OPF-060 | Error | Duplicate entry in the ZIP file: "…" (file names must be unique after Unicode canonical normalization and full case folding). |
OPF-062 | Uso | Found Adobe page-map attribute on spine element in opf file. |
OPF-063 | Advertencia | Referenced Adobe page-map item "…" was not found in the manifest. |
OPF-064 | Información | OPF declares type "…", validating using profile "…". |
OPF-065 | Error | Invalid metadata declaration, probably due to a cycle in "refines" metadata. |
OPF-066 | Error | Missing "dc:source" or "source-of" pagination metadata. The pagination source must be identified using the "dc:source" and "source-of" properties when the content includes page break markers. |
OPF-067 | Error | The resource "…" must not be listed both as a "link" element in the package metadata and as a manifest item. |
OPF-070 | Advertencia | Custom collection role "…" is an invalid URL. |
OPF-071 | Error | Index collections must only contain resources pointing to XHTML Content Documents. |
OPF-072 | Uso | Metadata element "…" is empty. |
OPF-073 | Error | External identifiers must not appear in the document type declaration. |
OPF-074 | Error | Package resource "…" is declared in several manifest items. |
OPF-075 | Error | Preview collections must only point to EPUB Content Documents. |
OPF-076 | Error | The URI of preview collections link elements must not include EPUB canonical fragment identifiers. |
OPF-077 | Advertencia | A Data Navigation Document should not be included in the spine. |
OPF-078 | Error | An EPUB Dictionary must contain at least one Content Document with dictionary content (epub:type "dictionary"). |
OPF-079 | Advertencia | Dictionary content was found (epub:type "dictionary"), the Package Document should declare the dc:type "dictionary". |
OPF-080 | Advertencia | A Search Key Map document file name should have the extension ".xml". |
OPF-081 | Error | Resource "…" (referenced from an EPUB Dictionary collection) was not found. |
OPF-082 | Error | Found an EPUB Dictionary collection containing more than one Search Key Map Document. |
OPF-083 | Error | Found an EPUB Dictionary collection containing no Search Key Map Document. |
OPF-084 | Error | Found an EPUB Dictionary collection containing resource "…" which is neither a Search Key Map Document nor an XHTML Content Document. |
OPF-085 | Advertencia | "dc:identifier" value "…" is marked as a UUID, but is an invalid UUID. |
OPF-086 | Advertencia | Property "…" is deprecated. Consider using … instead. |
OPF-086b | Uso | epub:type value "…" is deprecated. Consider using … instead. |
OPF-086c | Advertencia | the "…" reserved prefix is deprecated. |
OPF-087 | Uso | epub:type value "…" is not allowed on documents of type "…". |
OPF-088 | Uso | Unrecognized epub:type value "…". |
OPF-089 | Error | The "alternate" link rel keyword cannot be paired with other keywords. |
OPF-090 | Uso | It is encouraged to use MIME media type "…" instead of "…". |
OPF-091 | Error | The item href URL must not have a fragment identifier. |
OPF-092 | Error | Language tag "…" is not well-formed: … |
OPF-093 | Error | The "media-type" attribute is required for linked resources located in the EPUB container |
OPF-094 | Error | The "media-type" attribute is required for "…" links. |
OPF-095 | Error | The "media-type" attribute of "voicing" links must be an audio MIME type, but found "…". |
OPF-096 | Error | Non-linear content must be reachable, but found no hyperlink to "…". |
OPF-096b | Uso | No hyperlink was found to non-linear document "…", please check that it can be reached from scripted content. |
OPF-097 | Uso | Resource "…" is listed in the manifest, but no reference to it was found in content documents. |
OPF-098 | Error | The "href" attribute must reference resources, not elements in the package document, but found URL "…". |
OPF-099 | Error | The manifest must not list the package document. |
OPF-100 | Uso | The "…" property only applies to pre-paginated content. |
HTM: documentos de XHTML
Los XHTML capítulos: DOCTYPE, entidades, espacios de nombres y vistas de diseño fijo.
| Código | Severidad por defecto | Mensaje |
|---|---|---|
HTM-001 | Error | Any publication resource that is an XML-based media type must be a valid XML 1.0 document. XML version found: …. |
HTM-002 | Advertencia | The installed xml parser doesn’t support xml version verification. Xml files must be a valid XML 1.0 document. |
HTM-003 | Error | External entities are not allowed in EPUB v3 documents. External entity declaration found: …. |
HTM-004 | Error | Irregular DOCTYPE: found "…", expected "…". |
HTM-005 | Uso | An external reference was found. |
HTM-007 | Advertencia | Empty or whitespace-only value of attribute ssml:ph. |
HTM-009 | Error | The DOCTYPE provided is obsolete or irregular and can be removed. |
HTM-010 | Uso | Namespace "…" is unusual for the prefix "epub". |
HTM-011 | Error | Entity is undeclared. |
HTM-025 | Advertencia | Non-registered URI scheme type found in href. |
HTM-044 | Uso | Namespace uri "…" was included but not used. |
HTM-045 | Uso | Encountered empty href. |
HTM-046 | Error | Fixed layout document has no "viewport" meta element. |
HTM-047 | Error | Viewport metadata "…" has a syntax error |
HTM-048 | Error | SVG Fixed-Layout Documents must have a "viewBox" attribute (on the outermost "svg" element). |
HTM-051 | Advertencia | Found Microdata semantic enrichments but no RDFa. EDUPUB recommends using RDFa Lite. |
HTM-052 | Error | The property "region-based" is only allowed on nav elements in Data Navigation Documents. |
HTM_054 | Error | Custom attribute namespace ("…") must not include the string "…" in its domain. |
HTM_055 | Uso | The "…" element should not be used (discouraged construct) |
HTM_056 | Error | Viewport metadata has no "…" dimension (both "width" and "height" properties are required) |
HTM_057 | Error | Viewport "…" value must be a positive number or the keyword "device-…" |
HTM_058 | Error | HTML documents must be encoded in UTF-8, but UTF-16 was detected. |
HTM_059 | Error | Viewport "…" property must not be defined more than once, but found values […]. |
HTM_060a | Uso | EPUB reading systems must ignore secondary viewport meta elements in fixed-layout documents; viewport declaration "…" will be ignored. |
HTM_060b | Uso | EPUB reading systems must ignore viewport meta elements in reflowable documents; viewport declaration "…" will be ignored. |
HTM_061 | Error | "…" is not a valid custom data attribute (it must have at least one character after the hyphen, be XML-compatible, and not contain ASCII uppercase letters). |
HTM_062 | Uso | SVG "xlink:href" attribute is deprecated; an "href" attribute should be used instead. |
HTM_063 | Uso | SVG "xlink:href" attribute value ("…") should be equal to the "href" attribute value ("…"). |
CSS: Hojas de estilo
Archivos CSS y elementos de estilo: propiedades prohibidas, codificaciones, fuentes y sintaxis.
| Código | Severidad por defecto | Mensaje |
|---|---|---|
CSS-001 | Error | The "…" property must not be included in an EPUB Style Sheet. |
CSS-002 | Error | Empty or NULL reference found. |
CSS-003 | Advertencia | CSS document is encoded in UTF-16. It should be encoded in UTF-8 instead. |
CSS-004 | Error | CSS documents must be encoded in UTF-8, detected …; |
CSS-005 | Uso | Conflicting alternate style tags found: …. |
CSS-006 | Uso | CSS selector specifies fixed position. |
CSS-007 | Información | Font-face reference "…" refers to non-standard font type "…". |
CSS-008 | Error | An error occurred while parsing the CSS: …. |
CSS-015 | Error | Alternative style sheets must have a title. |
CSS-019 | Advertencia | CSS font-face declaration has no attributes. |
CSS-028 | Uso | Use of Font-face declaration. |
CSS-029 | Uso | Found CSS class name "…" but no "…" property was declared in the package document. |
CSS-030 | Error | The package document declares media overlays styling class names but no CSS was found in the content document. |
NCX: NCX (EPUB 2 tabla de contenido)
La tabla de contenido NCX heredada.
MED: Imágenes, audio y superposiciones de medios
Enlaces de imagen conservados de una página web (clic para agrandar).
| Código | Severidad por defecto | Mensaje |
|---|---|---|
MED-003 | Error | Picture "img" elements must reference core media type resources, but found resource "…" of type "…". |
MED-004 | Error | Image file header may be corrupted. |
MED-005 | Error | Media Overlay audio reference … to non-standard audio type … found. |
MED-008 | Error | The time specified in the clipBegin attribute must not be after clipEnd. |
MED-009 | Error | The time specified in the clipBegin attribute must not be the same as clipEnd. |
MED_007 | Error | Picture "source" elements must define a "type" attribute when they reference foreign resources; found resource "…" of type "…". |
MED_010 | Error | EPUB Content Documents referenced from a Media Overlay must specify the "media-overlay" attribute. |
MED_011 | Error | EPUB Content Document referenced from multiple Media Overlay Documents. |
MED_012 | Error | The "media-overlay" attribute does not match the ID of the Media Overlay that refers to this document. |
MED_013 | Error | Media Overlay Document referenced from the "media-overlay" attribute does not contain a reference to this Content Document. |
MED_014 | Error | Media overlay audio file URLs must not have a fragment, but found '#…'. |
MED_015 | Uso | Media overlay text references must be in reading order. Text target "…" is before the previous link target in … order. |
MED_016 | Advertencia | Media Overlays total duration should be the sum of the durations of all Media Overlays documents. |
MED_017 | Advertencia | URL fragment should indicate an element ID, but found '#…'. |
MED_018 | Advertencia | URL fragment should be an SVG fragment identifier, but found '#…'. |
ACC: Accesibilidad
Comprobaciones de accesibilidad en documentos de contenido (la mayoría están suprimidas por defecto).
| Código | Severidad por defecto | Mensaje |
|---|---|---|
ACC-004 | Suprimido | Html "a" element must have text. |
ACC-005 | Suprimido | Table heading cells should be identified by "th" elements for accessibility. |
ACC-006 | Suprimido | Tables should include a "thead" element for accessibility. |
ACC-007 | Suprimido | Content Documents do not use "epub:type" attributes for semantic inflection. |
ACC-009 | Uso | MathML should either have an "alttext" attribute or "annotation-xml" child element. |
ACC-011 | Uso | SVG hyperlink has no accessible name |
ACC-012 | Suprimido | Table elements should include a caption element. |
OBS: Características obsoletas
Funciones que aún funcionan pero están desactualizadas.
| Código | Severidad por defecto | Mensaje |
|---|---|---|
OBS-001 | Uso | Usage of … is outdated. |
INF: Información
Notas sobre EPUBCheck mismo.
| Código | Severidad por defecto | Mensaje |
|---|---|---|
INF-001 | Información | Rule … is under review and its severity may change in a future release. See the discussion at … |
CHK: EPUBCheck configuración
Problemas con el archivo de mensaje personalizado de EPUBCheck, no con el EPUB.
| Código | Severidad por defecto | Mensaje |
|---|---|---|
CHK-001 | Error | The custom message overrides file was not found. |
CHK-002 | Error | Unrecognized custom message id … encountered in message overrides file "…". |
CHK-003 | Error | Unrecognized custom message severity "…" encountered in message overrides file "…". |
CHK-004 | Error | The custom message contains too many parameters in message overrides file "…". |
CHK-005 | Error | The custom suggestion contains too many parameters in message overrides file "…". |
CHK-006 | Error | Unable to parse the custom format parameter in message overrides file "…". |
CHK-007 | Error | Error encountered while processing custom message file "…": "…". |
CHK-008 | Error | Error encountered while processing an item "…"; skip other checks for the item. |
IDs de mensajes retirados
Estos ID aún existen en la lista de mensajes de EPUBCheck pero no tienen texto y están suprimidos por defecto, por lo que EPUBCheck nunca los informa a menos que un archivo de mensaje personalizado los active.
ACC-001, ACC-002, ACC-003, ACC-008, ACC-010, ACC-013, ACC-014, ACC-015, ACC-016, ACC-017, CSS-009, CSS-010, CSS-011, CSS-012, CSS-013, CSS-016, CSS-017, CSS-020, CSS-021, CSS-022, CSS-023, CSS-024, CSS-025, HTM-006, HTM-008, HTM-012, HTM-013, HTM-014, HTM-014a, HTM-015, HTM-016, HTM-017, HTM-018, HTM-019, HTM-020, HTM-021, HTM-022, HTM-023, HTM-024, HTM-027, HTM-028, HTM-029, HTM-033, HTM-036, HTM-038, HTM-049, HTM-050, HTM_053, MED-001, MED-002, MED_006, NAV-002, NCX-002, NCX-003, NCX-005, OPF-008, OPF-009, OPF-019, OPF-020, OPF-046, OPF-056, OPF-058, OPF-059, OPF-068, OPF-069, RSC-018, RSC-023, SCP-001, SCP-002, SCP-003, SCP-004, SCP-005, SCP-006, SCP-007, SCP-008, SCP-009, SCP-010
Fuente y licencia
Los textos de los mensajes y las severidades por defecto provienen de EPUBCheck 5.4.0, el validador EPUB del W3C, publicado bajo la licencia BSD-3-Clause. Copyright © 2007 Adobe Systems Incorporated. Copyright © 2008 IDPF. Copyright © 2017 W3C (MIT, ERCIM, Keio, Beihang). github.com/w3c/epubcheck
Las causas y soluciones son escritas por EpubCC. Los códigos sin explicación muestran solo el mensaje oficial y no se ofrecen a los motores de búsqueda hasta que escribimos uno. EpubCC no está afiliado con el W3C.