diff --git a/core/ui/AdvancedSearch/Filter.tid b/core/ui/AdvancedSearch/Filter.tid
index 9703d9ca6..72c4f5074 100644
--- a/core/ui/AdvancedSearch/Filter.tid
+++ b/core/ui/AdvancedSearch/Filter.tid
@@ -7,7 +7,7 @@ caption: {{$:/language/Search/Filter/Caption}}
 
 <<lingo Filter/Hint>>
 
-<div class="tw-search tw-advanced-search"><$edit-text tiddler="$:/temp/advancedsearch" type="search" tag="input"/> <$button popup=<<qualify "$:/state/filterDropdown">> class="btn-invisible">{{$:/core/images/down-arrow}}</$button> <$reveal state="$:/temp/advancedsearch" type="nomatch" text=""> <$link to="" class="btn-invisible">{{$:/core/images/close-button}}</$link></$reveal></div>
+<div class="tw-search tw-advanced-search"><$edit-text tiddler="$:/temp/advancedsearch" type="search" tag="input"/> <$button popup=<<qualify "$:/state/filterDropdown">> class="tc-btn-invisible">{{$:/core/images/down-arrow}}</$button> <$reveal state="$:/temp/advancedsearch" type="nomatch" text=""> <$link to="" class="tc-btn-invisible">{{$:/core/images/close-button}}</$link></$reveal></div>
 
 <div class="tw-block-dropdown-wrapper">
 <$reveal state=<<qualify "$:/state/filterDropdown">> type="nomatch" text="" default="">
diff --git a/core/ui/AdvancedSearch/Shadows.tid b/core/ui/AdvancedSearch/Shadows.tid
index 39d170c1c..54781683e 100644
--- a/core/ui/AdvancedSearch/Shadows.tid
+++ b/core/ui/AdvancedSearch/Shadows.tid
@@ -7,7 +7,7 @@ caption: {{$:/language/Search/Shadows/Caption}}
 
 <<lingo Shadows/Hint>>
 
-<div class="tw-search"><$edit-text tiddler="$:/temp/advancedsearch" type="search" tag="input"/><$reveal state="$:/temp/advancedsearch" type="nomatch" text=""> <$link to="" class="btn-invisible">{{$:/core/images/close-button}}</$link></$reveal></div>
+<div class="tw-search"><$edit-text tiddler="$:/temp/advancedsearch" type="search" tag="input"/><$reveal state="$:/temp/advancedsearch" type="nomatch" text=""> <$link to="" class="tc-btn-invisible">{{$:/core/images/close-button}}</$link></$reveal></div>
 
 </$linkcatcher>
 
diff --git a/core/ui/AdvancedSearch/Standard.tid b/core/ui/AdvancedSearch/Standard.tid
index d93da904f..0b81afc0d 100644
--- a/core/ui/AdvancedSearch/Standard.tid
+++ b/core/ui/AdvancedSearch/Standard.tid
@@ -7,7 +7,7 @@ caption: {{$:/language/Search/Standard/Caption}}
 
 <<lingo Standard/Hint>>
 
-<div class="tw-search"><$edit-text tiddler="$:/temp/advancedsearch" type="search" tag="input"/><$reveal state="$:/temp/advancedsearch" type="nomatch" text=""> <$link to="" class="btn-invisible">{{$:/core/images/close-button}}</$link></$reveal></div>
+<div class="tw-search"><$edit-text tiddler="$:/temp/advancedsearch" type="search" tag="input"/><$reveal state="$:/temp/advancedsearch" type="nomatch" text=""> <$link to="" class="tc-btn-invisible">{{$:/core/images/close-button}}</$link></$reveal></div>
 
 </$linkcatcher>
 
diff --git a/core/ui/AdvancedSearch/System.tid b/core/ui/AdvancedSearch/System.tid
index 17d080798..c6921b74d 100644
--- a/core/ui/AdvancedSearch/System.tid
+++ b/core/ui/AdvancedSearch/System.tid
@@ -7,7 +7,7 @@ caption: {{$:/language/Search/System/Caption}}
 
 <<lingo System/Hint>>
 
-<div class="tw-search"><$edit-text tiddler="$:/temp/advancedsearch" type="search" tag="input"/><$reveal state="$:/temp/advancedsearch" type="nomatch" text=""> <$link to="" class="btn-invisible">{{$:/core/images/close-button}}</$link></$reveal></div>
+<div class="tw-search"><$edit-text tiddler="$:/temp/advancedsearch" type="search" tag="input"/><$reveal state="$:/temp/advancedsearch" type="nomatch" text=""> <$link to="" class="tc-btn-invisible">{{$:/core/images/close-button}}</$link></$reveal></div>
 
 </$linkcatcher>
 
diff --git a/core/ui/AlertTemplate.tid b/core/ui/AlertTemplate.tid
index 051729e45..c2c34d730 100644
--- a/core/ui/AlertTemplate.tid
+++ b/core/ui/AlertTemplate.tid
@@ -2,7 +2,7 @@ title: $:/core/ui/AlertTemplate
 
 <div class="tw-alert">
 <div class="tw-alert-toolbar">
-<$button message="tw-delete-tiddler" class="btn-invisible">
+<$button message="tw-delete-tiddler" class="tc-btn-invisible">
 {{$:/core/images/delete-button}}</$button>
 </div>
 <div class="tw-alert-subtitle">
diff --git a/core/ui/ControlPanel/Plugins.tid b/core/ui/ControlPanel/Plugins.tid
index a476a9290..bb885d194 100644
--- a/core/ui/ControlPanel/Plugins.tid
+++ b/core/ui/ControlPanel/Plugins.tid
@@ -18,12 +18,12 @@ $:/config/Plugins/Disabled/$(currentTiddler)$
 \define plugin-table-body(type,disabledMessage)
 <div class="tw-plugin-info-chunk">
 <$reveal type="nomatch" state=<<popup-state>> text="yes">
-<$button class="btn-invisible btn-dropdown" set=<<popup-state>> setTo="yes">
+<$button class="tc-btn-invisible btn-dropdown" set=<<popup-state>> setTo="yes">
 {{$:/core/images/right-arrow}}
 </$button>
 </$reveal>
 <$reveal type="match" state=<<popup-state>> text="yes">
-<$button class="btn-invisible btn-dropdown" set=<<popup-state>> setTo="no">
+<$button class="tc-btn-invisible btn-dropdown" set=<<popup-state>> setTo="no">
 {{$:/core/images/down-arrow}}
 </$button>
 </$reveal>
diff --git a/core/ui/EditTemplate/fields.tid b/core/ui/EditTemplate/fields.tid
index 7c5a51a96..5bc00bc8f 100644
--- a/core/ui/EditTemplate/fields.tid
+++ b/core/ui/EditTemplate/fields.tid
@@ -21,7 +21,7 @@ $:/config/EditTemplateFields/Visibility/$(currentField)$
 <$edit-text tiddler=<<currentTiddler>> field=<<currentField>> placeholder={{$:/language/EditTemplate/Fields/Add/Value/Placeholder}}/>
 </td>
 <td class="tw-edit-field-remove">
-<$button message="tw-remove-field" param=<<currentField>> class="btn-invisible">{{$:/core/images/delete-button}}</$button>
+<$button message="tw-remove-field" param=<<currentField>> class="tc-btn-invisible">{{$:/core/images/delete-button}}</$button>
 </td>
 </tr>
 </$list>
diff --git a/core/ui/EditTemplate/tags.tid b/core/ui/EditTemplate/tags.tid
index 5c9c15ca6..69f1bb4f3 100644
--- a/core/ui/EditTemplate/tags.tid
+++ b/core/ui/EditTemplate/tags.tid
@@ -9,14 +9,14 @@ background-color:$(backgroundColor)$;
 <$fieldmangler>
 <$list filter="[all[current]tags[]sort[title]]" storyview="pop"><$set name="backgroundColor" value={{!!color}}><span style=<<tag-styles>> class="tw-tag-label">
 <$view field="title" format="text" />
-<$button message="tw-remove-tag" param={{!!title}} class="btn-invisible tw-remove-tag-button">&times;</$button></span>
+<$button message="tw-remove-tag" param={{!!title}} class="tc-btn-invisible tw-remove-tag-button">&times;</$button></span>
 </$set>
 </$list>
 
 <div class="tw-edit-add-tag">
 <span class="tw-add-tag-name">
 <$edit-text tiddler="$:/temp/NewTagName" tag="input" default="" placeholder={{$:/language/EditTemplate/Tags/Add/Placeholder}} focusPopup=<<qualify "$:/state/popup/tags-auto-complete">> class="tw-edit-texteditor"/>
-</span> <$button popup=<<qualify "$:/state/popup/tags-auto-complete">> class="btn-invisible btn-dropdown">{{$:/core/images/down-arrow}}</$button> <span class="tw-add-tag-button">
+</span> <$button popup=<<qualify "$:/state/popup/tags-auto-complete">> class="tc-btn-invisible btn-dropdown">{{$:/core/images/down-arrow}}</$button> <span class="tw-add-tag-button">
 <$button message="tw-add-tag" param={{$:/temp/NewTagName}} set="$:/temp/NewTagName" setTo="" class="">
 <<lingo Tags/Add/Button>>
 </$button>
diff --git a/core/ui/EditTemplate/type.tid b/core/ui/EditTemplate/type.tid
index 476d42cc3..d5515bba8 100644
--- a/core/ui/EditTemplate/type.tid
+++ b/core/ui/EditTemplate/type.tid
@@ -2,7 +2,7 @@ title: $:/core/ui/EditTemplate/type
 tags: $:/tags/EditTemplate
 
 \define lingo-base() $:/language/EditTemplate/
-<p><$fieldmangler><em class="tw-edit"><<lingo Type/Prompt>></em> <$edit-text field="type" tag="input" default="" placeholder={{$:/language/EditTemplate/Type/Placeholder}} focusPopup=<<qualify "$:/state/popup/type-dropdown">> class="tw-edit-typeeditor"/> <$button popup=<<qualify "$:/state/popup/type-dropdown">> class="btn-invisible btn-dropdown">{{$:/core/images/down-arrow}}</$button> <$button message="tw-remove-field" param="type" class="btn-invisible btn-icon">{{$:/core/images/delete-button}}</$button></$fieldmangler></p>
+<p><$fieldmangler><em class="tw-edit"><<lingo Type/Prompt>></em> <$edit-text field="type" tag="input" default="" placeholder={{$:/language/EditTemplate/Type/Placeholder}} focusPopup=<<qualify "$:/state/popup/type-dropdown">> class="tw-edit-typeeditor"/> <$button popup=<<qualify "$:/state/popup/type-dropdown">> class="tc-btn-invisible btn-dropdown">{{$:/core/images/down-arrow}}</$button> <$button message="tw-remove-field" param="type" class="tc-btn-invisible btn-icon">{{$:/core/images/delete-button}}</$button></$fieldmangler></p>
 
 <div class="tw-block-dropdown-wrapper">
 <$reveal state=<<qualify "$:/state/popup/type-dropdown">> type="nomatch" text="" default="">
diff --git a/core/ui/ImportListing.tid b/core/ui/ImportListing.tid
index 66c080ae7..2f62ae9dc 100644
--- a/core/ui/ImportListing.tid
+++ b/core/ui/ImportListing.tid
@@ -30,12 +30,12 @@ selection-$(payloadTiddler)$
 </td>
 <td>
 <$reveal type="nomatch" state=<<previewPopupState>> text="yes">
-<$button class="btn-invisible btn-dropdown" set=<<previewPopupState>> setTo="yes">
+<$button class="tc-btn-invisible btn-dropdown" set=<<previewPopupState>> setTo="yes">
 {{$:/core/images/right-arrow}}&nbsp;<$text text=<<payloadTiddler>>/>
 </$button>
 </$reveal>
 <$reveal type="match" state=<<previewPopupState>> text="yes">
-<$button class="btn-invisible btn-dropdown" set=<<previewPopupState>> setTo="no">
+<$button class="tc-btn-invisible btn-dropdown" set=<<previewPopupState>> setTo="no">
 {{$:/core/images/down-arrow}}&nbsp;<$text text=<<payloadTiddler>>/>
 </$button>
 </$reveal>
diff --git a/core/ui/MissingTemplate.tid b/core/ui/MissingTemplate.tid
index 11b387547..bfd48df01 100644
--- a/core/ui/MissingTemplate.tid
+++ b/core/ui/MissingTemplate.tid
@@ -1,7 +1,7 @@
 title: $:/core/ui/MissingTemplate
 
 <div class="tw-tiddler-missing">
-<$button popup=<<qualify "$:/state/popup/missing">> class="btn-invisible tw-missing-tiddler-label">
+<$button popup=<<qualify "$:/state/popup/missing">> class="tc-btn-invisible tw-missing-tiddler-label">
 <$view field="title" format="text" />
 </$button>
 <$reveal state=<<qualify "$:/state/popup/missing">> type="popup" position="below" animate="yes">
diff --git a/core/ui/PageControls/more-page-actions.tid b/core/ui/PageControls/more-page-actions.tid
index 24ffe8380..3018d9e9f 100644
--- a/core/ui/PageControls/more-page-actions.tid
+++ b/core/ui/PageControls/more-page-actions.tid
@@ -22,7 +22,7 @@ $:/config/PageControlButtons/Visibility/$(listItem)$
 
 <$set name="tw-config-toolbar-text" value="yes">
 
-<$set name="tw-config-toolbar-class" value="btn-invisible">
+<$set name="tw-config-toolbar-class" value="tc-btn-invisible">
 
 <$list filter="[all[shadows+tiddlers]tag[$:/tags/PageControls]!has[draft.of]] -[[$:/core/ui/Buttons/more-page-actions]]" variable="listItem">
 
diff --git a/core/ui/PageTemplate.tid b/core/ui/PageTemplate.tid
index 3ce5cad36..ff451f227 100644
--- a/core/ui/PageTemplate.tid
+++ b/core/ui/PageTemplate.tid
@@ -10,7 +10,7 @@ tw-page-container tw-page-view-$(themeTitle)$ tw-language-$(languageTitle)$
 
 <$set name="tw-config-toolbar-text" value={{$:/config/Toolbar/Text}}>
 
-<$set name="tw-config-toolbar-class" value="btn-invisible">
+<$set name="tw-config-toolbar-class" value="tc-btn-invisible">
 
 <$set name="themeTitle" value={{$:/view}}>
 
diff --git a/core/ui/SideBar/Open.tid b/core/ui/SideBar/Open.tid
index 4c4a7e0ce..8050ba1e5 100644
--- a/core/ui/SideBar/Open.tid
+++ b/core/ui/SideBar/Open.tid
@@ -5,8 +5,8 @@ caption: {{$:/language/SideBar/Open/Caption}}
 \define lingo-base() $:/language/CloseAll/
 <$list filter="[list[$:/StoryList]]" history="$:/HistoryList" storyview="pop">
 
-<$button message="tw-close-tiddler" title={{$:/language/Buttons/Close/Hint}} aria-label={{$:/language/Buttons/Close/Caption}} class="btn-invisible btn-mini">&times;</$button> <$link to={{!!title}}><$view field="title"/></$link>
+<$button message="tw-close-tiddler" title={{$:/language/Buttons/Close/Hint}} aria-label={{$:/language/Buttons/Close/Caption}} class="tc-btn-invisible btn-mini">&times;</$button> <$link to={{!!title}}><$view field="title"/></$link>
 
 </$list>
 
-<$button message="tw-close-all-tiddlers" class="btn-invisible btn-mini"><<lingo Button>></$button>
+<$button message="tw-close-all-tiddlers" class="tc-btn-invisible btn-mini"><<lingo Button>></$button>
diff --git a/core/ui/SideBarLists.tid b/core/ui/SideBarLists.tid
index e10c1d8e2..b90b9f66a 100644
--- a/core/ui/SideBarLists.tid
+++ b/core/ui/SideBarLists.tid
@@ -6,10 +6,10 @@ title: $:/core/ui/SideBarLists
 <$edit-text tiddler="$:/temp/search" type="search" tag="input"/>
 <$reveal state="$:/temp/search" type="nomatch" text="">
 <$linkcatcher to="$:/temp/search">
-<$link to="" class="btn-invisible">{{$:/core/images/close-button}}</$link>
+<$link to="" class="tc-btn-invisible">{{$:/core/images/close-button}}</$link>
 </$linkcatcher>
 </$reveal>
-<$reveal state="$:/temp/search" type="match" text="">&nbsp;<$link to="$:/AdvancedSearch" tooltip={{$:/language/Buttons/AdvancedSearch/Hint}} aria-label={{$:/language/Buttons/AdvancedSearch/Caption}} class="btn-invisible">&hellip;</$link>
+<$reveal state="$:/temp/search" type="match" text="">&nbsp;<$link to="$:/AdvancedSearch" tooltip={{$:/language/Buttons/AdvancedSearch/Hint}} aria-label={{$:/language/Buttons/AdvancedSearch/Caption}} class="tc-btn-invisible">&hellip;</$link>
 </$reveal>
 </div>
 
diff --git a/core/ui/TagManager.tid b/core/ui/TagManager.tid
index 9e56fd011..88b2cc0b3 100644
--- a/core/ui/TagManager.tid
+++ b/core/ui/TagManager.tid
@@ -10,7 +10,7 @@ title: $:/TagManager
 \end
 \define iconEditor(title)
 <div class="tw-drop-down-wrapper">
-<$edit-text field="icon" tag="input" size="20"/> <$button popup=<<qualify "$:/state/popup/icon/$title$">> class="btn-invisible btn-dropdown">{{$:/core/images/down-arrow}}</$button>
+<$edit-text field="icon" tag="input" size="20"/> <$button popup=<<qualify "$:/state/popup/icon/$title$">> class="tc-btn-invisible btn-dropdown">{{$:/core/images/down-arrow}}</$button>
 <$reveal state=<<qualify "$:/state/popup/icon/$title$">> type="popup" position="belowleft" text="" default="">
 <div class="tw-drop-down">
 <$linkcatcher to="$title$!!icon">
diff --git a/core/ui/TagTemplate.tid b/core/ui/TagTemplate.tid
index b5111f891..4896ef3d1 100644
--- a/core/ui/TagTemplate.tid
+++ b/core/ui/TagTemplate.tid
@@ -5,7 +5,7 @@ background-color:$(backgroundColor)$;
 \end
 <span class="tw-tag-list-item">
 <$set name="backgroundColor" value={{!!color}}>
-<$button popup=<<qualify "$:/state/popup/tag">> class="btn-invisible tw-tag-label" style=<<tag-styles>>>
+<$button popup=<<qualify "$:/state/popup/tag">> class="tc-btn-invisible tw-tag-label" style=<<tag-styles>>>
 <$transclude tiddler={{!!icon}}/> <$view field="title" format="text" />
 </$button>
 </$set>
diff --git a/core/ui/TopRightBar/menu.tid b/core/ui/TopRightBar/menu.tid
index 2ce068e9b..4e3f71146 100644
--- a/core/ui/TopRightBar/menu.tid
+++ b/core/ui/TopRightBar/menu.tid
@@ -2,8 +2,8 @@ title: $:/core/ui/TopBar/menu
 tags: $:/tags/TopRightBar
 
 <$reveal state="$:/state/sidebar" type="nomatch" text="no">
-<$button set="$:/state/sidebar" setTo="no" title={{$:/language/Buttons/HideSideBar/Hint}} aria-label={{$:/language/Buttons/HideSideBar/Caption}} class="btn-invisible">{{$:/core/images/chevron-right}}</$button>
+<$button set="$:/state/sidebar" setTo="no" title={{$:/language/Buttons/HideSideBar/Hint}} aria-label={{$:/language/Buttons/HideSideBar/Caption}} class="tc-btn-invisible">{{$:/core/images/chevron-right}}</$button>
 </$reveal>
 <$reveal state="$:/state/sidebar" type="match" text="no">
-<$button set="$:/state/sidebar" setTo="yes" title={{$:/language/Buttons/ShowSideBar/Hint}} aria-label={{$:/language/Buttons/ShowSideBar/Caption}} class="btn-invisible">{{$:/core/images/chevron-left}}</$button>
+<$button set="$:/state/sidebar" setTo="yes" title={{$:/language/Buttons/ShowSideBar/Hint}} aria-label={{$:/language/Buttons/ShowSideBar/Caption}} class="tc-btn-invisible">{{$:/core/images/chevron-left}}</$button>
 </$reveal>
diff --git a/core/ui/UntaggedTemplate.tid b/core/ui/UntaggedTemplate.tid
index 0318241f6..77fae8a42 100644
--- a/core/ui/UntaggedTemplate.tid
+++ b/core/ui/UntaggedTemplate.tid
@@ -1,7 +1,7 @@
 title: $:/core/ui/UntaggedTemplate
 
 \define lingo-base() $:/language/SideBar/
-<$button popup=<<qualify "$:/state/popup/tag">> class="btn-invisible tw-untagged-label tw-tag-label">
+<$button popup=<<qualify "$:/state/popup/tag">> class="tc-btn-invisible tw-untagged-label tw-tag-label">
 <<lingo Tags/Untagged/Caption>>
 </$button>
 <$reveal state=<<qualify "$:/state/popup/tag">> type="popup" position="below">
diff --git a/core/wiki/macros/toc.tid b/core/wiki/macros/toc.tid
index 8edfbec93..60c6d73f6 100644
--- a/core/wiki/macros/toc.tid
+++ b/core/wiki/macros/toc.tid
@@ -21,12 +21,12 @@ tags: $:/tags/Macro
 <li>
 <$link>
 <$reveal type="nomatch" state=<<toc-state>> text="open">
-<$button set=<<toc-state>> setTo="open" class="btn-invisible">
+<$button set=<<toc-state>> setTo="open" class="tc-btn-invisible">
 {{$:/core/images/right-arrow}}
 </$button>
 </$reveal>
 <$reveal type="match" state=<<toc-state>> text="open">
-<$button set=<<toc-state>> setTo="close" class="btn-invisible">
+<$button set=<<toc-state>> setTo="close" class="tc-btn-invisible">
 {{$:/core/images/down-arrow}}
 </$button>
 </$reveal>
@@ -55,12 +55,12 @@ tags: $:/tags/Macro
 <$link>
 <$list filter="[all[current]tagging[]limit[1]]">
 <$reveal type="nomatch" state=<<toc-state>> text="open">
-<$button set=<<toc-state>> setTo="open" class="btn-invisible">
+<$button set=<<toc-state>> setTo="open" class="tc-btn-invisible">
 {{$:/core/images/right-arrow}}
 </$button>
 </$reveal>
 <$reveal type="match" state=<<toc-state>> text="open">
-<$button set=<<toc-state>> setTo="close" class="btn-invisible">
+<$button set=<<toc-state>> setTo="close" class="tc-btn-invisible">
 {{$:/core/images/down-arrow}}
 </$button>
 </$reveal>
diff --git a/editions/tw5.com/tiddlers/TableOfContents.tid b/editions/tw5.com/tiddlers/TableOfContents.tid
index 52161d843..bb9428404 100644
--- a/editions/tw5.com/tiddlers/TableOfContents.tid
+++ b/editions/tw5.com/tiddlers/TableOfContents.tid
@@ -8,11 +8,11 @@ type: text/vnd.tiddlywiki
 
 \define toc-heading(caption,body)
 <$reveal type="nomatch" state=<<qualify "$:/state/toc/$caption$">> text="show">
-<$button set=<<qualify "$:/state/toc/$caption$">> setTo="show" class="btn-invisible">{{$:/core/images/right-arrow}} $caption$
+<$button set=<<qualify "$:/state/toc/$caption$">> setTo="show" class="tc-btn-invisible">{{$:/core/images/right-arrow}} $caption$
 </$button>
 </$reveal>
 <$reveal type="match" state=<<qualify "$:/state/toc/$caption$">> text="show">
-<$button set=<<qualify "$:/state/toc/$caption$">> setTo="hide" class="btn-invisible">{{$:/core/images/down-arrow}} $caption$
+<$button set=<<qualify "$:/state/toc/$caption$">> setTo="hide" class="tc-btn-invisible">{{$:/core/images/down-arrow}} $caption$
 </$button>
 </$reveal>
 <$reveal type="match" state=<<qualify "$:/state/toc/$caption$">> text="show" retain="yes" animate="yes">
diff --git a/editions/tw5.com/tiddlers/howtos/Creating SubStories.tid b/editions/tw5.com/tiddlers/howtos/Creating SubStories.tid
index fda62af04..4d103ad79 100644
--- a/editions/tw5.com/tiddlers/howtos/Creating SubStories.tid	
+++ b/editions/tw5.com/tiddlers/howtos/Creating SubStories.tid	
@@ -16,7 +16,7 @@ Click this link to get started: HelloThere
 <$list filter="[list[MySubStoryList]]" history="MySubHistoryList">
 <div>
 
-! <$button message="tw-close-tiddler" class="btn-invisible">{{$:/core/images/close-button}}</$button> <$view field="title"/>
+! <$button message="tw-close-tiddler" class="tc-btn-invisible">{{$:/core/images/close-button}}</$button> <$view field="title"/>
 
 <$transclude/>
 </div>
@@ -34,7 +34,7 @@ Click this link to get started: HelloThere
 <$list filter="[list[MySubStoryList]]" history="MySubHistoryList">
 <div>
 
-! <$button message="tw-close-tiddler" class="btn-invisible">{{$:/core/images/close-button}}</$button> <$view field="title"/>
+! <$button message="tw-close-tiddler" class="tc-btn-invisible">{{$:/core/images/close-button}}</$button> <$view field="title"/>
 
 <$transclude/>
 
diff --git a/editions/tw5.com/tiddlers/mechanisms/HistoryMechanism.tid b/editions/tw5.com/tiddlers/mechanisms/HistoryMechanism.tid
index 14d7bd987..2ab55c7a2 100644
--- a/editions/tw5.com/tiddlers/mechanisms/HistoryMechanism.tid
+++ b/editions/tw5.com/tiddlers/mechanisms/HistoryMechanism.tid
@@ -13,7 +13,7 @@ The history list also maintains the field ''current-tiddler'' that contains the
 ```
 <$list filter="[list[$:/StoryList]]" history="$:/HistoryList" storyview="pop">
 
-<$button message="tw-close-tiddler" class="btn-invisible btn-mini">&times;</$button> <$link to={{!!title}}><$view field="title"/> <$reveal type="match" state="$:/HistoryList!!current-tiddler" text=<<currentTiddler>>>&#x2713;</$reveal></$link>
+<$button message="tw-close-tiddler" class="tc-btn-invisible btn-mini">&times;</$button> <$link to={{!!title}}><$view field="title"/> <$reveal type="match" state="$:/HistoryList!!current-tiddler" text=<<currentTiddler>>>&#x2713;</$reveal></$link>
 
 </$list>
 ```
@@ -22,6 +22,6 @@ Which renders the same as the "Open" sidebar tab, with the addition of a tick ag
 
 <$list filter="[list[$:/StoryList]]" history="$:/HistoryList" storyview="pop">
 
-<$button message="tw-close-tiddler" class="btn-invisible btn-mini">&times;</$button> <$link to={{!!title}}><$view field="title"/> <$reveal type="match" state="$:/HistoryList!!current-tiddler" text=<<currentTiddler>>>&#x2713;</$reveal></$link>
+<$button message="tw-close-tiddler" class="tc-btn-invisible btn-mini">&times;</$button> <$link to={{!!title}}><$view field="title"/> <$reveal type="match" state="$:/HistoryList!!current-tiddler" text=<<currentTiddler>>>&#x2713;</$reveal></$link>
 
 </$list>
diff --git a/editions/tw5.com/tiddlers/mechanisms/StateMechanism.tid b/editions/tw5.com/tiddlers/mechanisms/StateMechanism.tid
index 4366c57c2..adaac24e9 100644
--- a/editions/tw5.com/tiddlers/mechanisms/StateMechanism.tid
+++ b/editions/tw5.com/tiddlers/mechanisms/StateMechanism.tid
@@ -28,7 +28,7 @@ Note how this approach makes the ''open'' tab in the sidebar very easy to implem
 
 ```
 <$list filter="[list[$:/StoryList]]" history="$:/HistoryList" storyview="pop">
-<$button message="tw-close-tiddler" class="btn-invisible btn-mini">&times;</$button> <$link to={{!!title}}><$view field="title"/></$link>
+<$button message="tw-close-tiddler" class="tc-btn-invisible btn-mini">&times;</$button> <$link to={{!!title}}><$view field="title"/></$link>
 </$list>
 ```
 
diff --git a/themes/tiddlywiki/vanilla/base.tid b/themes/tiddlywiki/vanilla/base.tid
index 23a3b3783..b7088b2fa 100644
--- a/themes/tiddlywiki/vanilla/base.tid
+++ b/themes/tiddlywiki/vanilla/base.tid
@@ -247,7 +247,7 @@ button svg, button img {
 	vertical-align: middle;
 }
 
-.btn-invisible {
+.tc-btn-invisible {
 	padding: 0;
 	margin: 0;
 	background: none;
@@ -642,7 +642,7 @@ button.tw-tag-label, span.tw-tag-label {
 	fill: <<colour tiddler-controls-foreground-selected>>;
 }
 
-.tw-tiddler-controls button.btn-invisible:hover svg {
+.tw-tiddler-controls button.tc-btn-invisible:hover svg {
 	fill: <<colour tiddler-controls-foreground-hover>>;
 }
 
@@ -879,7 +879,7 @@ canvas.tw-edit-bitmapeditor  {
 	fill: <<colour foreground>>;
 }
 
-.tw-drop-down button.btn-invisible:hover svg {
+.tw-drop-down button.tc-btn-invisible:hover svg {
 	fill: <<colour foreground>>;
 }