This Lua module is used in system messages, and on approximately 23,200,000 pages, or roughly 35% of all pages. Changes to it can cause immediate changes to the Wikipedia user interface. To avoid major disruption and server load, any changes should be tested in the module's /sandbox or /testcases subpages, or in your own module sandbox. The tested changes can be added to this page in a single edit. Please discuss changes on the talk page before implementing them.

This module is rated as ready for general use. It has reached a mature state, is considered relatively stable and bug-free, and may be used wherever appropriate. It can be mentioned on help pages and other Wikipedia resources as an option for new users. To minimise server load and avoid disruptive output, improvements should be developed through sandbox testing rather than repeated trial-and-error editing.

This module can only be edited by administrators because it is transcluded onto one or more cascade-protected pages.

This module depends on the following other modules: Module:If preview (sandbox)

Module:Check for unknown parameters is used to check for uses of unknown parameters in a template or module. It may be appended to a template at the end or called directly from a module.

To sort entries into a tracking category by parameter, use:

• {{#invoke:Check for unknown parameters|check|unknown=[[Category:Some tracking category|_VALUE_]]|arg1|arg2|arg3|argN}}

To sort the entries into a tracking category by parameter with a preview error message, use:

• {{#invoke:Check for unknown parameters|check|unknown=[[Category:Some tracking category|_VALUE_]]|preview=unknown parameter "_VALUE_"|arg1|arg2|...|argN}}

For an explicit red error message, use:

• {{#invoke:Check for unknown parameters|check|unknown=<span class="error">Sorry, I don't recognize _VALUE_</span>|arg1|arg2|...|argN}}

To use Lua patterns, use:

• {{#invoke:Check for unknown parameters|check|unknown=[[Category:Some tracking category|_VALUE_]]|preview=unknown parameter "_VALUE_"|arg1|arg2|...|argN|regexp1=header[%d]+|regexp2=date[1-9]}}

To call from a module, use:

local checkForUnknownParameters = require("Module:Check for unknown parameters")
local result = checkForUnknownParameters._check(validArgs, args)

Where the first set of args are the module args below and the second set of args are the parameters that are checked.

• arg1, arg2, ..., argN, are the known parameters.
• Unnamed (positional) parameters can be added too: |1|2|arg1|arg2|....
• Lua patterns (similar to regular expressions) usage with parameters is also supported (such as: |regexp1=header[%d]+, |regexp2=date[1-9], |regexp3=data[%d]+[abc]?). This is useful when there are many known parameters which use a systematic pattern.
• |unknown= – what happens when an unknown parameter is used. Typically use either a tracking category to place pages that use unknown parameters, or an error.
• |preview= – the text to be displayed when in preview mode and an unknown parameter is used.
• The _VALUE_ keyword, if used, will be changed to the name of the parameter. This is useful for either sorting the entries in a tracking category, or for provide more explicit information.
• |ignoreblank=1 – by default, the module makes no distinction between a defined-but-blank parameter and a non-blank parameter. That is, both unlisted |foo=x and |foo= are reported. To only track non-blank parameters use |ignoreblank=1. If you clean your arguments with Module:Arguments and call this module afterwards, you need not use this parameter as that module ignores blank arguments by default.
• |showblankpositional=1 – by default, the module ignores blank positional parameters. That is, an unlisted |2= is ignored. To include blank positional parameters in the tracking use |showblankpositional=1.
• |mapframe_args= – When this is set to a non-null value, the various Module:Infobox mapframe parameters will be automatically included in the list of valid parameters. This eliminates the need to manually add all 20+ params. NOTE this should only be used when {{#invoke:Infobox mapframe|autoWithCation}} is in the template calling Check for unknown. Do NOT use if using {{Infobox mapframe}} as not all parameters are included when calling the template.

{{Infobox
| above = {{{name|}}}

| label1 = Height
| data1 = {{{height|}}}

| label2 = Weight
| data2 = {{{weight|}}}

| label3 = Website
| data3 = {{{website|}}}
}}<!-- 
  end infobox, start tracking
-->{{#invoke:Check for unknown parameters|check
| unknown = {{Main other|[[Category:Some tracking category|_VALUE_]]}}
| preview = unknown parameter "_VALUE_" | height | name | website | weight 
}}

See the end of Module:Rugby box for a simple example or Module:Infobox3cols or Module:Flag for more complicated examples.

• Category:Unknown parameters (315) (category page can have header {{Unknown parameters category}})
• Template:Checks for unknown parameters – adds documentation to templates using this module
• Module:Check for deprecated parameters – similar module that checks for deprecated parameters
• Module:Check for conflicting parameters – module that checks for conflicting parameters
• Module:TemplatePar – similar function (originally from dewiki)
• Template:Parameters and Module:Parameters – generates a list of parameter names for a given template
• Project:TemplateData based template parameter validation
• Module:Parameter validation checks a lot more

• User:Bamyers99/TemplateParametersTool - A tool for checking usage of template parameters
• User:Zackmann08/scripts/AddCheckForUnknownParameters and User:Frietjes/addcheckforunknownparameters.js, scripts for to quickly and easily generate wikitext for {{#invoke:Check for unknown parameters|check}} with the parameters in the template