Matterhorn Protocol

Artifact is tagged as real content.

Real content is marked as artifact.

Content marked as Artifact is present inside tagged content.

Tagged content is present inside content marked as Artifact.

Content is neither marked as Artifact nor tagged as real content.

The structure type and attributes of a structure element are not semantically appropriate for the structure element. All of the following structure types must be taken into account: Document, Part, Art, Sect, Div, BlockQuote, Caption, TOC, TOCI, Index, NonStruct, Private, P, H, H1, H2, H3, H4, H5, H6, L, LI, Lbl, LBody, Table, TR, TH, TD, THead, TBody, TFoot, Span, Quote, Note, Reference, BibEntry, Code, Link, Annot, Ruby, Warichu, RB, RT, RP, WT, WP, Figure, Formula, Form.

NOTE 1: Structure type is not semantically appropriate if the nature of the content inside the structure element does not match the structure type of the structure element.

NOTE 2: For any non-standard structure types, the standard structure type to which the type is role-mapped shall be used for validation.

NOTE 3: Tables are regular when the number of logical cells is equal in each row after accounting for rowspan and colspan attributes. While PDF/UA-1 does not prohibit irregular tables, irregular tables are almost always a strong indicator of improper table structure. It may be a good idea to raise a warning when such tables are encountered, but it is not required by the Matterhorn Protocol.

NOTE 4: The value of table cell attributes is a function of the cell’s semantic role in the table’s structure. Therefore, a TH cell may not include a Scope attribute with an inappropriate value.

One or more non-standard tag’s mapping does not terminate with a standard type.

NOTE: Although PDF/UA defines the nomenclature for heading levels above H6 (Hn), these are not standard structure types (as defined in ISO 32000-1) and therefore Hn tags must (PDF/UA-1 7.1, paragraph 1) be rolemapped to a standard structure type. According to PDF/UA-1, PDF/UA-conforming processors are expected to ignore such mappings and respect the heading level.

The mapping of one or more non-standard types is semantically inappropriate.

A circular mapping exists.

One or more standard types are remapped.

One or more Actions lead to flickering.

One or more multimedia objects contain flickering content.

One or more JavaScript actions lead to flickering.

Information is conveyed by contrast, color, format or layout, or some combination thereof but the content is not tagged to reflect all meaning conveyed by the use of contrast, color, format or layout, or some combination thereof.

Media annotation present, but audio content not available in another form.

NOTE: An example of another form is a transcript.

Audio annotation present, but content not available in another form.

NOTE: An example of another form is a transcript.

JavaScript uses beep function but does not provide another means of notification.

Document does not contain XMP metadata stream

The metadata stream in the Catalog dictionary does not include the PDF/UA identifier.

Metadata stream does not contain dc:title

dc:title does not clearly identify the document

ViewerPreferences dictionary of the Catalog dictionary does not contain DisplayDocTitle key.

ViewerPreferences dictionary of the Catalog dictionary contains DisplayDocTitle key with a value of false.

OCR-generated text contains significant errors.

OCR-generated text is not tagged

Suspect entry has a value of true.

Tags are not in logical reading order.

Structure elements are nested in a semantically inappropriate manner. (e.g. a table inside a heading).

The structure type (after applying any role-mapping as necessary) of a structure element is not semantically appropriate.

A table-related structure element is used in a way that does not conform to the syntax defined in ISO 32000-1, Table 337.

A list-related structure element is used in a way that does not conform to Table 336 in ISO 32000-1.

A TOC-related structure element is used in a way that does not conform to Table 333 in ISO 32000-1.

A Ruby-related structure element is used in a way that does not conform to Table 338 in ISO 32000-1.

A Warichu-related structure element is used in a way that does not conform to Table 338 in ISO 32000-1.

Character code cannot be mapped to Unicode.

Natural language for text in page content cannot be determined.

Natural language for text in “Alt”, “ActualText” and “E” attributes cannot be determined.

Natural language in the Outline entries cannot be determined.

Natural language in the “Contents” entry for annotations cannot be determined.

Natural language in the TU key for form fields cannot be determined.

Natural language for document metadata cannot be determined.

Natural language is not appropriate.

Stretched characters are not represented appropriately.

Graphics objects other than text objects and artifacts are not tagged with a Figure tag.

A link with a meaningful background does not include alternative text describing both the link and the graphic’s purpose.

A caption is not tagged with a Caption tag.

Figure tag alternative or replacement text missing.

Actual text used for a Figure for which Alternative text is more appropriate.

Graphics objects that possess semantic value only within a group of graphics objects is tagged on its own.

A more accessible representation is not used.

Headings are not tagged.

Does use numbered headings, but the first heading tag is not H1.

Numbered heading levels in descending sequence are skipped (Example: H3 follows directly after H1).

Numbered heading tags do not use Arabic numerals.

Content representing a 7th level (or higher) heading does not use an “H7” (or higher) tag.

A node contains more than one H tag.

Document uses both H and H# tags.

NOTE: In weakly-structured documents, headings always take the form “Hn” (e.g. H1, H2, Hn) without intervening whitespace or numerical separators.

A row has a header cell, but that header cell is not tagged as a header.

A column has a header cell, but that header cell is not tagged as a header.

In a table not organized with Headers attributes and IDs, a TH cell does not contain a Scope attribute.

Content is tagged as a table for information that is not organized in rows and columns.

A given cell’s header cannot be unambiguously determined.

List is an ordered list, but no value for the ListNumbering attribute is present.

List is an ordered list, but the ListNumbering value is not one of the following: Decimal, UpperRoman, LowerRoman, UpperAlpha, LowerAlpha.

Content is a list but is not tagged as a list.

Content is a mathematical expression but is not tagged with a Formula tag.

Formula tag is missing an Alt attribute.

Unicode mapping requirements are not met.

Headers and footers are not marked as pagination artifacts.

Header or footer artifacts are not classified as Header or Footer subtypes.

Footnotes, endnotes, note labels are not tagged as Note.

References are not tagged as Reference.

ID key of the Note tag is not present.

ID key of the Note tag is non-unique.

Name entry is missing or has an empty string as its value in an Optional Content Configuration Dictionary in the Configs entry in the OCProperties entry in the Catalog dictionary.

Name entry is missing or has an empty string as its value in an Optional Content Configuration Dictionary that is the value of the D entry in the OCProperties entry in the Catalog dictionary.

The AS key appears in an Optional Content Configuration Dictionary.

The file specification dictionary for an embedded file does not contain F and UF keys.

Article threads do not reflect logical reading order.

No test specific to digital signatures is required, however other provisions apply (form fields).

Non-interactive forms are not tagged with the PrintFields attribute.

File contains the dynamicRender element with value “required”.

The file is encrypted but does not contain a P key in its encryption dictionary.

The file is encrypted and does contain a P key but the 10th bit position of the P key is false.

No tests specific to navigation are required; use appropriate semantics.

An annotation whose hidden flag is not set and whose rectangle is not outside the crop-box is not in correct reading order.

An annotation, excluding annotations of subtype Widget, Popup or Link, is not nested within an Annot tag.

An annotation whose hidden flag is not set and whose rectangle is not outside the crop-box is used for visual formatting but is not tagged according to its semantic function.

An annotation other than annotations of type Link, Widget or Popup whose hidden flag is not set and whose rectangle is not outside the crop box and does not have a Contents key does not have an alternative description (in the form of an Alt entry in the enclosing structure element).

A form field whose hidden flag is not set and whose rectangle is not outside the crop-box and does not have a TU key does not have an alternative description (in the form of an Alt entry in the enclosing structure element).

An annotation with subtype undefined in ISO 32000 does not meet 7.18.1.

An annotation of subtype TrapNet exists.

A page containing an annotation does not contain a Tabs key.

A page containing an annotation has a Tabs key with a value other than S.

A widget annotation is not nested within a Form tag.

A link annotation is not nested within a Link tag.

A link annotation does not include an alternate description in the Contents Key.

The IsMap key is present with a value of true but the functionality is not provided in some other way.

CT key is missing from the media clip data dictionary.

Alt key is missing from the media clip data dictionary.

File attachment annotations do not conform to 7.11.

A PrinterMark annotation is included in logical structure.

The appearance stream of a PrinterMark annotation is not marked as Artifact.

A script requires specific timing for individual keystrokes.

A reference XObject is present.

Form XObject contains MCIDs and is referenced more than once.

A Type 0 font dictionary with encoding other than Identity-H and Identity-V has values for Registry in both CIDSystemInfo dictionaries that are not identical.

A Type 0 font dictionary with encoding other than Identity-H and Identity-V has values for Ordering in both CIDSystemInfo dictionaries that are not identical.

A Type 0 font dictionary with encoding other than Identity-H and Identity-V has a value for Supplement in the CIDSystemInfo dictionary of the CID font that is less than the value for Supplement in the CIDSystemInfo dictionary of the CMap.

A Type 2 CID font contains neither a stream nor the name Identity as the value of the CIDToGIDMap entry.

A Type 2 CID font does not contain a CIDToGIDMap entry.

A CMap is neither listed as described in ISO 32000- 1:2008, 9.7.5.2, Table 118 nor is it embedded.

The WMode entry in a CMap dictionary is not identical to the WMode value in the CMap stream.

A CMap references another CMap which is not listed in ISO 32000-1:2008, 9.7.5.2, Table 118.

NOTE: For more information see ISO 32000-1 9.7.5.3, UseCMap entry.

For a font used by text intended to be rendered the font program is not embedded.

NOTE: A glyph is used for rendering if the text render mode is not equal 3 (text render mode 3 is used for invisible text).

A font program is embedded that is not legally embeddable for unlimited, universal rendering.

For a font used by text the font program is embedded but it does not contain glyphs for all of the glyphs referenced by the text used for rendering.

NOTE: A glyph is used for rendering if the text render mode is not equal to 3 (text render mode 3 is used for invisible text).

The FontDescriptor dictionary of an embedded Type 1 font contains a CharSet string, but at least one of the glyphs present in the font program is not listed in the CharSet string.

The FontDescriptor dictionary of an embedded Type 1 font contains a CharSet string, but at least one of the glyphs listed in the CharSet string is not present in the font program.

The FontDescriptor dictionary of an embedded CID font contains a CIDSet string, but at least one of the glyphs present in the font program is not listed in the CIDSet string.

The FontDescriptor dictionary of an embedded CID font contains a CIDSet string, but at least one of the glyphs listed in the CIDSet string is not present in the font program.

For one or more glyphs, the glyph width information in the font dictionary and in the embedded font program differ by more than 1/1000 unit.

A non-symbolic TrueType font is used for rendering, but none of the cmap entries in the embedded font program is a non-symbolic cmap.

A non-symbolic TrueType font is used for rendering, but for at least one glyph to be rendered the glyph cannot be looked up by any of the non-symbolic cmap entries in the embedded font program.

The font dictionary for a non-symbolic TrueType font does not contain an Encoding entry.

The font dictionary for a non-symbolic TrueType font contains an Encoding dictionary which does not contain a BaseEncoding entry.

The value for either the Encoding entry or the BaseEncoding entry in the Encoding dictionary in a non-symbolic TrueType font dictionary is neither MacRomanEncoding nor WinAnsiEncoding.

The Differences array in the Encoding entry in a non-symbolic TrueType font dictionary contains one or more glyph names which are not listed in the Adobe Glyph List.

The Differences array is present in the Encoding entry in a non-symbolic TrueType font dictionary but the embedded font program does not contain a (3,1) Microsoft Unicode cmap.

The Encoding entry is present in the font dictionary for a symbolic TrueType font.

The embedded font program for a symbolic TrueType font contains no cmap.

The embedded font program for a symbolic TrueType font contains more than one cmap, but none of the cmap entries is a (3,1) Microsoft Symbol cmap.

A font dictionary does not contain the ToUnicode entry and none of the following is true: - the font uses MacRomanEncoding, MacExpertEncoding or WinAnsiEncoding - the font is a Type 1 or Type 3 font and the glyph names of the glyphs referenced are all contained in the Adobe Glyph List or the set of named characters in the Symbol font, as defined in ISO 32000-1:2008, Annex D - the font is a Type 0 font, and its descendant CIDFont uses Adobe-GB1, Adobe-CNS1, AdobeJapan1 or Adobe-Korea1 character collections - the font is a non-symbolic TrueType font

One or more Unicode values specified in the ToUnicode CMap are zero (0).

One or more Unicode values specified in the ToUnicode CMap are equal to either U+FEFF or U+FFFE.

One or more characters used in text showing operators reference the .notdef glyph.