Help: CS1 errors

==<span id="invisible_char">&lt;char> character in |&lt;param>= at position ''n''</span>==
<section begin="invisible_char_help_text" />{{help desk}}{{#invoke:Cs1 documentation support|help_text_error_messages|err_invisible_char|$1=&lt;char> character|$2=<code class="cs1-code">{{pipe}}&lt;param>=</code>|$3={{var|n}}}}

This error is reported for citations with parameter values that contain invisible or non-printable characters known as [[control character]]s; the error includes the position at which the character can be found.  [[Module:Citation/CS1]] detects parameter values that contain any of these characters:

* [[non-breaking space]], U+00A0
* [[soft hyphen]], U+00AD
* [[replacement character]], U+FFFD
* [[hair space]], U+200A
* [[zero-width space]], U+200B
* [[zero-width joiner]], U+200D (note that these are permitted as part of emoji modifiers; see note below)
* [[horizontal tab]], U+0009 (HT)
* [[line feed]], U+0010 (LF)
* [[carriage return]], U+0013 (CR)
* [[delete character]], U+007F (DEL)
* [[C0 and C1 control codes|C0 control]], U+0000–U+001F (NULL–US)
* [[C0 and C1 control codes|C1 control]], U+0080–U+009F (XXX–APC)

To resolve invisible-character errors, remove or replace the identified character. Most intentional white-space characters should be replaced with a normal space character (i.e. press your keyboard's space bar). See [[MOS:NBSP]] for guidance on insertion of intentional non-breaking spaces.  

Because these characters are mostly invisible, the error message identifies the character's position in the parameter value counted from the left. Space characters between the assignment operator (the '=' sign) and the parameter value are not counted. If you move through the citation with the arrow keys then the cursor may stand still once at an invisible character, which can be removed with {{keypress|Delete}} or {{keypress|Backspace}}. If you copy-paste a string to the "Characters" field at https://r12a.github.io/app-conversion/ and click "View in UniView" then the position and name of all characters is shown.

[[Zero-width joiner]] characters (U+200D) are used as a valid part of emoji modification (for example, adding a skull emoji to a flag emoji to create a pirate flag emoji). When new modifiers are added to the emoji character set, which happens one or two times per year, those modifiers need to be added to the Citation Style 1 "Configuration" module. Editors can request this addition at [[Help talk:Citation Style 1]]. 

{{#invoke:Cs1 documentation support|help_text_error_messages|err_invisible_char|$1=&lt;name> stripmarker|$2=<code class="cs1-code">{{pipe}}&lt;param>=</code>|$3={{var|n}}}}

[[Help:Strip markers|Strip markers]] are special sequences of characters that [[MediaWiki]] inserts as a place-holder for certain [[XML]]-like tags.  These tags include {{tag|gallery}}, {{tag|math}}, {{tag|nowiki}}, {{tag|pre}}, and {{tag|ref}}.  The strip markers are replaced with content before the final page rendering.  The module ignores math and nowiki strip markers.

To resolve strip marker errors, remove or replace the identified tag.  The error message identifies the strip marker's position in the parameter value counted from the left.  Space characters between the assignment operator (the '=' sign) and the parameter value are not counted when calculating the position.

Strip marker errors can also be caused by unsupported additional text or templates in parameter values{{mdash}}for example, {{tl|ISBN}} in {{para|title}}. Resolve the problem by moving the extraneous text outside the citation template, or by removing the extraneous text or template markup, as appropriate.

Pages with this error are automatically placed in {{#invoke:cs1 documentation support|help_text_cats|err_invisible_char|pages=yes}}.<ref group="lower-alpha" name="categories" /><section end="invisible_char_help_text" />
Description	What you type	What you get
Italic	''Italic text''	Italic text
Bold	'''Bold text'''	Bold text
Bold & italic	'''''Bold & italic text'''''	*Bold & italic text*
Description	What you type	What you get
Reference	Page text.<ref>[https://www.example.org/ Link text], additional text.</ref>	Page text.^[1]
Named reference	Page text.<ref name="test">[https://www.example.org/ Link text]</ref>	Page text.^[2]
Additional use of the same reference	Page text.<ref name="test" />	Page text.^[2]
Display references	<references />	↑ Link text, additional text. ↑ Link text