"$1" is already added as "$2". Please check the options in the sidebar. This is due to either the use of [//www.mediawiki.org/wiki/Special:MyLanguage/Help:TemplateData#aliases aliases] or [//www.mediawiki.org/wiki/Special:MyLanguage/Help:TemplateData#label labels].
If known, enter [//www.mediawiki.org/wiki/Special:MyLanguage/Help:VisualEditor/User_guide#Adding_undocumented_parameters undocumented parameter] names. Note that only parameters known by the template will have an effect. You may find information about existing parameters on the [[$1|template's page]].
Templates provide formatting for content. This editor shows what options a template provides on the left and values can then be added to those options on the right.
You are currently editing a template and one or more pieces of [//www.mediawiki.org/wiki/Special:MyLanguage/Help:VisualEditor/User_guide#Editing_multi-part_template_content connected content] (wikitext and/or additional templates).
This template is missing [//www.mediawiki.org/wiki/Special:MyLanguage/Help:VisualEditor/User_guide#Template_parameters TemplateData], and its parameters have been [//www.mediawiki.org/wiki/Special:MyLanguage/Help:VisualEditor/User_guide#Autogenerated_parameters autogenerated]. As a result the template and its parameters lack descriptions. There might be additional information on the [[$1|template's page]].
Press Space to add or remove parameters. Press Enter to add a parameter and immediately edit its value. When a parameter is already selected, press Enter to edit the value.