Wikipedia:WikiProject Check Wikipedia/List of errors

Check Wikipedia

Toolforge

List of Errors

Discussion

Data for the list is compiled from the following locations: WPCleaner • AutoWikiBrowser • Auto-Formatter   Fixes all cases     Warns of an error and fixes some cases     Warns of an error # Priority Cosmetic? Error name WPC AWB AF Category Reason 01 Low Yes Template contains useless word template: Y Y Y Syntax error Article contains a template that includes the redundant prefix "template:" (eg. {{Template:reflist}}). Removing it is usually useful when copying page in another Wikipedia. 02 High No <br>, <center> or <small> tag with incorrect syntax. Cases of <span /> and <div />. Y Y Y Syntax error A <br> or <br /> tag (note the slash) are the only standard formats. See the HTML standard for <br> or <small>. Mediawiki's Tidy tool will be replaced causing many now valid tags, such as </br> and <center />, to no longer work. 03 High No Reference list missing Y Display problem The article contains one or more <ref> tags, but is missing a {{Reflist}} or <references /> tag 04 Mid No HTML text style element <a> Y The article contains one or more <a> tags. <a> tags will not show up in the rendered article and should use normal wikilink code for external links. 05 High No Comment tag with no correct end Display problem Missing closing comment tag. <!-- --> 06 Low Yes DEFAULTSORT with special characters Y Y Y Syntax error Don't use special lettering in DEFAULTSORT 07 Mid No Headlines all start with three "=" Y Y Accessibility First headline starts with "=== XY ===". It should be "== XY ==" header. This causes organisational and accessibility problems. 08 High No Headline should end with "=" Y Y Display problem Headline should end with "=". 09 Low Yes Categories multiple in one line Y Y Y Against convention Two or more categories in one line. 10 High No Square brackets with no correct end Y Y Display problem Found a "[[" brackets with no corresponding "]]" brackets. 11 Off HTML named entities Y Y Source readability HTML code found where a Unicode character could be used. For example, &auml; used instead of ä. It is difficult to comprehend for beginners. 12 Low Yes HTML list elements Source readability Detection <ol>, <ul>...</ul> or <li> tags. Sometimes it is necessary to have these tags, especially in infoboxes. 13 High No <math> tag without correct match Display problem Missing </math> or <math> tag. 14 High No <source> tag without correct match Display problem Missing </source> or <source> tag. 15 High No <code> tag without correct match Display problem Missing </code> or <code> tag. 16 Low Yes Unicode control characters Y Y Incident detection Detection of Unicode controls such as 0+FEFF, 0+200E, 0+200B and PUA characters. 17 Low Yes Category duplication Y Y Incident detection Unnecessary duplicate categories found. 18 Off Category's first letter is small Y Y Y 19 High No Headlines start with one "=" Y Accessibility A heading section starts with just one "=". This causes organisational and accessibility problems 20 Low Yes Symbol for dead Y Y Y Source readability The article had a &dagger; and not † 21 Off Category: in English Y Y Incident detection [[Category: ]] found when the native language should be used 22 Off Category with space Y Y Y Category contains an unnecessary space, for example: [[ Category:ABC]] or [[Category : ABC]]. 23 High No <nowiki> without correct match Display problem Missing </nowiki> or <nowiki> tag. 24 High No <pre> without correct match Display problem Missing </pre> or <pre> tag. 25 Mid No Headline hierarchy Y Y Accessibility After a section headline "==", there should not be a headline of "====". This causes organisational and accessibility problems. 26 Low Yes HTML text style element <b> (bold) Y Y Accessibility Source readability Found a <b> tag. Should use wiki markup of '''. See WP:Deviations 27 Off Unicode syntax Y Y Y Source readability 28 High No Table with no correct end Display problem An opening table has "{|" tag, but no corresponding closing "|}" tag. 29 High No <gallery> without correct match Display problem Missing </gallery> or <gallery> tag. 30 Off Image without alternate description Accessibility 31 Low Yes HTML table element Source readability A <table>, <tr> or <td> tag was found. Should use wiki markup instead. 32 High No Double pipe in a link Y Y Display problem Article contains a wikilink like [[text|text2|text3]] (displays as text2|text3), [[text||text3]] or [[text|text2||]]. or a broken wikilink inside a table. 33 Off HTML text style element <u> (underline) Y Against convention 34 High No Template programming element Y Syntax error A template programming element, such as {{{1}}}, #if or #switch, was found. They are usually not needed or a regular template can be substituted instead. 35 Off Image gallery without description Y Accessibility 36 Low Yes Redirect with incorrect syntax Y Y Display problem 37 Low Yes DEFAULTSORT missing for titles with special letters Y Y Display problem Don't use special lettering for sorting. DEFAULTSORT should be set without the special lettering. 38 Low Yes HTML text style element <i> (italics) Y Y Accessibility Source readability Found a <i> tag. Should use wiki markup of ''. See WP:Deviations 39 Low Yes HTML text style element <p> Y Accessibility Found a <p> tag. Usually should use wiki markup's blank line. Some tags, such as <ref> must use <p> due to a wikimedia bug. 40 Low Yes HTML text style element <font> Y Y Against convention Found a <font> tag. This tag isn't used in HTML5 41 Off HTML text style element <big> Against convention Found a <big> tag. This tag isn't used in HTML5 42 Low Yes HTML text style element <strike> Y Y Y Found a <strike> tag. This tag isn't used in HTML5. Use <s> instead. However, strikes shouldn't be used at all for accessibility reasons, so removing the strike is usually the best option. 43 High No Template with no correct end Y Y Display problem Found a "{{" brackets with no corresponding "}}" brackets. 44 Low Yes Headlines with bold Y Y Y Against convention A headline is all or partially bold. This should rarely be used and may or not be bold depending on the browser used. 45 Low Yes Interwiki duplication Y Y Display problem 46 High No Square brackets without correct beginning Y Display problem A broken wikilink was found. 47 High No Template without correct beginning Display problem Found a "}}" brackets with no corresponding "{{" brackets. 48 Low Yes Title linked in text Y Y A wikilink of the article's title was found. This creates an unnecessary circular wikilink per MOS:OVERLINK. 49 High No Headline with HTML Y Found a headline created with HTML tags <h1>, <h2>, etc. per MOS:DEVIATIONS and MOS:HEAD. 50 Off en dash or em dash Y Y 51 Mid No Interwiki before last headline Y Y Syntax error With interwikis no long used, this usually means a syntax problem with a interlanguage link, ie [[de:foo]] instead of [[:de:foo]] 52 Low Yes Category before last headline Y Y 53 Mid No Interwiki before last category Y Y Syntax error With interwikis no long used, this usually means a syntax problem with a interlanguage link, ie [[de:foo]] instead of [[:de:foo]] 54 Low Yes Break in list Y Y Y Accessibility WP:LISTGAP 55 Low Yes Double <small> tags Y Y Accessibility 56 Off Arrow as ASCII art Y The article had an arrow like "<--" or "-->" or "<==" or "==>". Write better this arrow with the Unicode "←" or "→" or "⇐" or "⇒". 57 Low Yes Headlines end with a colon Y Y Y 58 Mid No Headline all CAPS Y 59 Low Yes Template value ends with a <br> Y Y 60 High No Template parameter with a problem Syntax error Usually means a broken wikilink inside a template. Can also mean the '=' sign is missing and replaced with another character. 61 Low Yes Reference before punctuation Y Y Y Display problem See WP:REFPUNC 62 High No URL without http:// Y Syntax error A URL was found that contained no http://. Example: [en.wikipedia.org Wikipedia] 63 Low Yes <small> in a <ref>, <sub> or <sup> Y Y Y Accessibility <ref> and <sub> tags already create smaller text. Adding a <small> would cause the text to be smaller than 85%. This goes against accessibility guidelines. 64 Low Yes Link equal to linktext Y Y Y Syntax error Finds cases of [[Foo|Foo]]. A Visual Editor bug causes wikilinks with italics or bold to be done incorrectly, usually some text outside the wikilink will also be bold or italized. Moreover, WP:NOPIPEDLINK. 65 Low Yes Image description ends with <br> Y Y 66 Low Yes Image description with full <small> Y Y Accessibility Image description text is already smaller. Adding a <small> would cause the text to be smaller than 85%. This goes against accessibility guidelines. 67 Off Reference after punctuation (see 61 instead) Y 68 Off Link to other language Y 69 Mid No ISBN with incorrect syntax Y Y Y Incorrect content Per WP:ISBN, the correct format is ISBN 978-2345-78383-1. Also finds ISBNs inside external links as Wikimagick doesn't work and ISBN template can cause problems. 70 Mid No ISBN with wrong length Incorrect content 71 Mid No ISBN with wrong position of X Incorrect content 72 Mid No ISBN-10 with wrong checksum Incorrect content 73 Mid No ISBN-13 with wrong checksum Incorrect content 74 High No Link with no target Y Y 75 Off Indented list Y 76 Low Yes Link with encoded space Y Y Y Source readability Found a URI encoded space, ie %20, inside a wikilink. This usually indicates a badly constructed external link. 77 Off Image description with partial <small> Y 78 Low Yes Reference list duplication Display problem Found two or more {{reflist}} or <references /> tags 79 Off External link without description Y 80 High No External link with a line break Y Y Display problem Found a newline character inside an external link or a missing closing bracket. A newline character causes the link not to work. 81 Off Reference duplication Y Y 82 Off Link to other wikiproject 83 Mid No Headlines start with three "=" and later with two "=" Y Accessibility organisational and accessibility problems. 84 Off Section without content Y Y 85 Low Yes Tags without content Y Y 86 High No External link with two brackets Y Y Y Display problem Found an external links surround by double brackets. Example: [[http://www.wikipedia.org Wikipedia]] 87 Off HTML named entities without semicolon Y Y Display problem 88 Low Yes DEFAULTSORT with a blank at first position Y Y Y 89 Low Yes DEFAULTSORT with no space after the comma Y Syntax error The script found a DEFAULTSORT without a space after the comma {{DEFAULTSORT:DuBois,Lewis}}. The causes the article to be sorted as the first DuBois article. 90 Mid No Internal link written as an external link Y Y Syntax error The script found an external link that should be replaced with a wikilink. An example would be on enwiki [http://en.wikipedia.org/wiki/Larry_Wall Larry Wall] should be written as [[Larry Wall]]. 91 Mid No Interwiki link written as an external link Y Y Syntax error The script found an external link that should be replaced with an interwiki link. An example would be on enwiki [http://fr.wikipedia.org/wiki/Larry_Wall Larry Wall] should be written as [[:fr:Larry Wall]]. 92 Off Headline double Y 93 Mid No External link with double http:// Y Y Syntax error The script found an external link that had double http://. An example would be [http://http://www.google.com] 94 Mid No Reference tags with no correct match Y Display problem A <ref> or </ref> tag was found without the corresponding beginning or ending tag. 95 Low Yes Editor's signature or link to user or draft space Syntax error See Wikipedia:UPYES and WP:SIGNHERE 96 Mid No Table of Contents after first headline Accessibility TOC should be placed at the end of the lead section of the text, before the first section heading. Users of screen readers do not expect any text between the TOC and the first heading. See WP:TOC. 97 Mid No TOC has material after it and before the first headline Accessibility Screen readers don't process material that comes between the Table of Contents and first headline. See WP:TOC. 98 High No <sub> with no correct end Y Y Display problem Missing </sub> tag. Can cause display problems in Visual Editor and mw:Html5Depurate 99 High No <sup> with no correct end Y Y Display problem Missing </sup> tag. Can cause display problems in Visual Editor and mw:Html5Depurate 100 Low Yes List tag with no correct match Source readability List tag (<ol>, <ul> or <li>) with no correct match. 101 Low Yes Ordinal number found inside <sup> tags Y Against convention Ordinal numbers should be in regular text, not inside <sup> tags See MOS:ORDINAL. 102 Mid No PMID with incorrect syntax Y Y Y Incorrect content Per WP:PMID, the syntax should be PMID 4957203 Also checks if PMID is inside an external link as Magiclinks and {{PMID}} template won't work. 103 Mid No Pipe Template inside a wikilink Y Syntax error The magic word {{!}} shouldn't be used inside a wikilink. | should be used instead. 104 Mid No Unbalanced quotes in ref name Y Y Syntax error The script found unbalanced quotes in a reference tag. For example <ref name="ref 1> 105 High No Heading should begin with "=" Display problem A heading should begin with a "=". 106 Mid No ISSN with incorrect syntax Y Y Display problem The script found a problem with ISSN syntax. A normal ISSN looks like ISSN 3895-2372 or 3957-957X. There must be a - between the numbers (don't use dashes). Best if {{ISSN}} template is added. Also finds cases where the ISSN is inside an external linkss 107 Mid No ISSN with wrong length Incorrect content The script checked the ISSN and found it not containing 8 characters. ISSN should have 8 characters. 108 Mid No ISSN with wrong checksum Incorrect content The script checked the ISSN and found a problem with the checksum in the ISSN. Also see Category:Articles with invalid ISSNs. 109 High No Include tag error Display problem The script found a problem with opening or closing tags for <includeonly>, <onlyinclude> or <noinclude> tags. This can cause transclusion problems. 110 Off Include tag found Display problem The script found a <includeonly>, <onlyinclude> or <noinclude> tags. 111 Off Ref after last reference list Display problem There are <ref> tags, after the {{reflist}} or <references> tags. 112 Low Yes Bad or deprecated css attributes Display problem 113 Low Yes Newline inside a wikilink Display problem Found a newline character inside a wikilink. A newline character causes the wikilink not to work.