diff --git a/core/themes/classy/templates/block/block--search-form-block.html.twig b/core/themes/classy/templates/block/block--search-form-block.html.twig
index 399ddd7..0d1e08d 100644
--- a/core/themes/classy/templates/block/block--search-form-block.html.twig
+++ b/core/themes/classy/templates/block/block--search-form-block.html.twig
@@ -1,7 +1,7 @@
{#
/**
* @file
- * Default theme override for the search form block.
+ * Override for the search form block.
*
* Available variables:
* - plugin_id: The ID of the block implementation.
diff --git a/core/themes/classy/templates/block/block--system-branding-block.html.twig b/core/themes/classy/templates/block/block--system-branding-block.html.twig
index f648773..bb1ea35 100644
--- a/core/themes/classy/templates/block/block--system-branding-block.html.twig
+++ b/core/themes/classy/templates/block/block--system-branding-block.html.twig
@@ -2,7 +2,7 @@
{#
/**
* @file
- * Default theme implementation for a branding block.
+ * Implementation for a branding block.
*
* Each branding element variable (logo, name, slogan) is only available if
* enabled in the block configuration.
diff --git a/core/themes/classy/templates/block/block--system-menu-block.html.twig b/core/themes/classy/templates/block/block--system-menu-block.html.twig
index dff7e39..d9137da 100644
--- a/core/themes/classy/templates/block/block--system-menu-block.html.twig
+++ b/core/themes/classy/templates/block/block--system-menu-block.html.twig
@@ -1,7 +1,7 @@
{#
/**
* @file
- * Default theme implementation for a menu block.
+ * Implementation for a menu block.
*
* Available variables:
* - plugin_id: The ID of the block implementation.
diff --git a/core/themes/classy/templates/block/block.html.twig b/core/themes/classy/templates/block/block.html.twig
index aa750cb..14ed0fa 100644
--- a/core/themes/classy/templates/block/block.html.twig
+++ b/core/themes/classy/templates/block/block.html.twig
@@ -1,7 +1,7 @@
{#
/**
* @file
- * Default theme implementation to display a block.
+ * Implementation to display a block.
*
* Available variables:
* - plugin_id: The ID of the block implementation.
diff --git a/core/themes/classy/templates/content-edit/file-managed-file.html.twig b/core/themes/classy/templates/content-edit/file-managed-file.html.twig
index 9a33ae1..b76d182 100644
--- a/core/themes/classy/templates/content-edit/file-managed-file.html.twig
+++ b/core/themes/classy/templates/content-edit/file-managed-file.html.twig
@@ -1,7 +1,7 @@
{#
/**
* @file
- * Default theme implementation to display a file form widget.
+ * Implementation to display a file form widget.
*
* Available variables:
* - element: Form element for the file upload.
diff --git a/core/themes/classy/templates/content-edit/file-upload-help.html.twig b/core/themes/classy/templates/content-edit/file-upload-help.html.twig
index 8fa6b3e..2380a1e 100644
--- a/core/themes/classy/templates/content-edit/file-upload-help.html.twig
+++ b/core/themes/classy/templates/content-edit/file-upload-help.html.twig
@@ -1,7 +1,7 @@
{#
/**
* @file
- * Default theme implementation to display help text for file fields.
+ * Implementation to display help text for file fields.
*
* Available variables:
* - descriptions: Lines of help text for uploading a file.
diff --git a/core/themes/classy/templates/content-edit/file-widget-multiple.html.twig b/core/themes/classy/templates/content-edit/file-widget-multiple.html.twig
index 25534a5..a4f9ae0 100644
--- a/core/themes/classy/templates/content-edit/file-widget-multiple.html.twig
+++ b/core/themes/classy/templates/content-edit/file-widget-multiple.html.twig
@@ -1,7 +1,7 @@
{#
/**
* @file
- * Default theme implementation to display a multi file form widget.
+ * Implementation to display a multi file form widget.
*
* Available variables:
* - table: Table of previously uploaded files.
diff --git a/core/themes/classy/templates/content-edit/file-widget.html.twig b/core/themes/classy/templates/content-edit/file-widget.html.twig
index 892ed3d..7da190b 100644
--- a/core/themes/classy/templates/content-edit/file-widget.html.twig
+++ b/core/themes/classy/templates/content-edit/file-widget.html.twig
@@ -1,7 +1,7 @@
{#
/**
* @file
- * Default theme implementation to display a file widget.
+ * Implementation to display a file widget.
*
* Available variables:
* - element: Form element for the managed file.
diff --git a/core/themes/classy/templates/content-edit/filter-caption.html.twig b/core/themes/classy/templates/content-edit/filter-caption.html.twig
index eb9d248..492f7c0 100644
--- a/core/themes/classy/templates/content-edit/filter-caption.html.twig
+++ b/core/themes/classy/templates/content-edit/filter-caption.html.twig
@@ -1,7 +1,7 @@
{#
/**
* @file
- * Default theme implementation for a filter caption.
+ * Implementation for a filter caption.
*
* Returns HTML for a captioned image, audio, video or other tag.
*
diff --git a/core/themes/classy/templates/content-edit/filter-guidelines.html.twig b/core/themes/classy/templates/content-edit/filter-guidelines.html.twig
index 9459c1a..c6d1c03 100644
--- a/core/themes/classy/templates/content-edit/filter-guidelines.html.twig
+++ b/core/themes/classy/templates/content-edit/filter-guidelines.html.twig
@@ -1,7 +1,7 @@
{#
/**
* @file
- * Default theme implementation for guidelines for a text format.
+ * Implementation for guidelines for a text format.
*
* Available variables:
* - format: Contains information about the current text format, including the
diff --git a/core/themes/classy/templates/content-edit/filter-tips.html.twig b/core/themes/classy/templates/content-edit/filter-tips.html.twig
index b17de01..5ed5808 100644
--- a/core/themes/classy/templates/content-edit/filter-tips.html.twig
+++ b/core/themes/classy/templates/content-edit/filter-tips.html.twig
@@ -1,7 +1,7 @@
{#
/**
* @file
- * Default theme implementation for a set of filter tips.
+ * Implementation for a set of filter tips.
*
* Available variables:
* - tips: Descriptions and a CSS ID in the form of 'module-name/filter-id'
diff --git a/core/themes/classy/templates/content-edit/image-widget.html.twig b/core/themes/classy/templates/content-edit/image-widget.html.twig
index 8bdc5f1..f70aa14 100644
--- a/core/themes/classy/templates/content-edit/image-widget.html.twig
+++ b/core/themes/classy/templates/content-edit/image-widget.html.twig
@@ -1,7 +1,7 @@
{#
/**
* @file
- * Default theme implementation for an image field widget.
+ * Implementation for an image field widget.
*
* Available variables:
* - attributes: HTML attributes for the containing element.
diff --git a/core/themes/classy/templates/content-edit/node-add-list.html.twig b/core/themes/classy/templates/content-edit/node-add-list.html.twig
index 258d3e6..a41a224 100644
--- a/core/themes/classy/templates/content-edit/node-add-list.html.twig
+++ b/core/themes/classy/templates/content-edit/node-add-list.html.twig
@@ -1,7 +1,7 @@
{#
/**
* @file
- * Default theme implementation to list node types available for adding content.
+ * Implementation to list node types available for adding content.
*
* This list is displayed on the Add content admin page.
*
diff --git a/core/themes/classy/templates/content-edit/node-edit-form.html.twig b/core/themes/classy/templates/content-edit/node-edit-form.html.twig
index 6d8ac2a..af7e658 100644
--- a/core/themes/classy/templates/content-edit/node-edit-form.html.twig
+++ b/core/themes/classy/templates/content-edit/node-edit-form.html.twig
@@ -1,7 +1,7 @@
{#
/**
* @file
- * Default theme implementation for a node edit form.
+ * Implementation for a node edit form.
*
* Two column template for the node add/edit form.
*
diff --git a/core/themes/classy/templates/content-edit/text-format-wrapper.html.twig b/core/themes/classy/templates/content-edit/text-format-wrapper.html.twig
index 4e5ff6d..00c9f46 100644
--- a/core/themes/classy/templates/content-edit/text-format-wrapper.html.twig
+++ b/core/themes/classy/templates/content-edit/text-format-wrapper.html.twig
@@ -1,7 +1,7 @@
{#
/**
* @file
- * Default theme implementation for a text format-enabled form element.
+ * Implementation for a text format-enabled form element.
*
* Available variables:
* - children: Text format element children.
diff --git a/core/themes/classy/templates/content/aggregator-item.html.twig b/core/themes/classy/templates/content/aggregator-item.html.twig
index a3cda41..4c5a3a3 100644
--- a/core/themes/classy/templates/content/aggregator-item.html.twig
+++ b/core/themes/classy/templates/content/aggregator-item.html.twig
@@ -1,7 +1,7 @@
{#
/**
* @file
- * Default theme implementation to present a feed item in an aggregator page.
+ * Implementation to present a feed item in an aggregator page.
*
* Available variables:
* - url: URL to the originating feed item.
diff --git a/core/themes/classy/templates/content/book-node-export-html.html.twig b/core/themes/classy/templates/content/book-node-export-html.html.twig
index 0efa9a7..1a961a1 100644
--- a/core/themes/classy/templates/content/book-node-export-html.html.twig
+++ b/core/themes/classy/templates/content/book-node-export-html.html.twig
@@ -1,7 +1,7 @@
{#
/**
* @file
- * Default theme implementation for a single node in a printer-friendly outline.
+ * Implementation for a single node in a printer-friendly outline.
*
* Available variables:
* - node: Fully loaded node.
diff --git a/core/themes/classy/templates/content/comment.html.twig b/core/themes/classy/templates/content/comment.html.twig
index ba62e2b..ac944c2 100644
--- a/core/themes/classy/templates/content/comment.html.twig
+++ b/core/themes/classy/templates/content/comment.html.twig
@@ -1,7 +1,7 @@
{#
/**
* @file
- * Default theme implementation for comments.
+ * Implementation for comments.
*
* Available variables:
* - author: Comment author. Can be a link or plain text.
diff --git a/core/themes/classy/templates/content/mark.html.twig b/core/themes/classy/templates/content/mark.html.twig
index 2798bb0..ad90926 100644
--- a/core/themes/classy/templates/content/mark.html.twig
+++ b/core/themes/classy/templates/content/mark.html.twig
@@ -1,7 +1,7 @@
{#
/**
* @file
- * Default theme implementation for a marker for new or updated content.
+ * Implementation for a marker for new or updated content.
*
* Available variables:
* - status: Number representing the marker status to display. Use the constants
diff --git a/core/themes/classy/templates/content/node.html.twig b/core/themes/classy/templates/content/node.html.twig
index 76e521c..c5ba55a 100644
--- a/core/themes/classy/templates/content/node.html.twig
+++ b/core/themes/classy/templates/content/node.html.twig
@@ -1,7 +1,7 @@
{#
/**
* @file
- * Default theme implementation to display a node.
+ * Implementation to display a node.
*
* Available variables:
* - node: Full node entity.
diff --git a/core/themes/classy/templates/content/search-result.html.twig b/core/themes/classy/templates/content/search-result.html.twig
index 732489b..65308ff 100644
--- a/core/themes/classy/templates/content/search-result.html.twig
+++ b/core/themes/classy/templates/content/search-result.html.twig
@@ -1,7 +1,7 @@
{#
/**
* @file
- * Default theme implementation for displaying a single search result.
+ * Implementation for displaying a single search result.
*
* This template renders a single search result. The list of results is
* rendered using '#theme' => 'item_list', with suggestions of:
diff --git a/core/themes/classy/templates/content/taxonomy-term.html.twig b/core/themes/classy/templates/content/taxonomy-term.html.twig
index 2fbffa5..61d7b7b 100644
--- a/core/themes/classy/templates/content/taxonomy-term.html.twig
+++ b/core/themes/classy/templates/content/taxonomy-term.html.twig
@@ -1,7 +1,7 @@
{#
/**
* @file
- * Default theme implementation to display a taxonomy term.
+ * Implementation to display a taxonomy term.
*
* Available variables:
* - url: URL of the current term.
diff --git a/core/themes/classy/templates/dataset/aggregator-feed.html.twig b/core/themes/classy/templates/dataset/aggregator-feed.html.twig
index 1876c45..af4e08f 100644
--- a/core/themes/classy/templates/dataset/aggregator-feed.html.twig
+++ b/core/themes/classy/templates/dataset/aggregator-feed.html.twig
@@ -1,7 +1,7 @@
{#
/**
* @file
- * Default theme implementation to present an aggregator feed.
+ * Implementation to present an aggregator feed.
*
* The contents are rendered above feed listings when browsing source feeds.
* For example, "example.com/aggregator/sources/1".
diff --git a/core/themes/classy/templates/dataset/forum-icon.html.twig b/core/themes/classy/templates/dataset/forum-icon.html.twig
index b32b734..4a55580 100644
--- a/core/themes/classy/templates/dataset/forum-icon.html.twig
+++ b/core/themes/classy/templates/dataset/forum-icon.html.twig
@@ -1,7 +1,7 @@
{#
/**
* @file
- * Default theme implementation to display a status icon for a forum post.
+ * Implementation to display a status icon for a forum post.
*
* Available variables:
* - attributes: HTML attributes to be applied to the wrapper element.
diff --git a/core/themes/classy/templates/dataset/forum-list.html.twig b/core/themes/classy/templates/dataset/forum-list.html.twig
index 5b41f6a..96c74ce 100644
--- a/core/themes/classy/templates/dataset/forum-list.html.twig
+++ b/core/themes/classy/templates/dataset/forum-list.html.twig
@@ -1,7 +1,7 @@
{#
/**
* @file
- * Default theme implementation to display a list of forums and containers.
+ * Implementation to display a list of forums and containers.
*
* Available variables:
* - forums: A collection of forums and containers to display. It is keyed to
diff --git a/core/themes/classy/templates/dataset/forums.html.twig b/core/themes/classy/templates/dataset/forums.html.twig
index 1bb7c05..e23ce3f 100644
--- a/core/themes/classy/templates/dataset/forums.html.twig
+++ b/core/themes/classy/templates/dataset/forums.html.twig
@@ -1,7 +1,7 @@
{#
/**
* @file
- * Default theme implementation to display a forum.
+ * Implementation to display a forum.
*
* May contain forum containers as well as forum topics.
*
diff --git a/core/themes/classy/templates/dataset/item-list.html.twig b/core/themes/classy/templates/dataset/item-list.html.twig
index bd71e7f..56cbc19 100644
--- a/core/themes/classy/templates/dataset/item-list.html.twig
+++ b/core/themes/classy/templates/dataset/item-list.html.twig
@@ -1,7 +1,7 @@
{#
/**
* @file
- * Default theme implementation for an item list.
+ * Implementation for an item list.
*
* Available variables:
* - items: A list of items. Each item contains:
diff --git a/core/themes/classy/templates/dataset/table.html.twig b/core/themes/classy/templates/dataset/table.html.twig
index 3d0252e..b2b6898 100644
--- a/core/themes/classy/templates/dataset/table.html.twig
+++ b/core/themes/classy/templates/dataset/table.html.twig
@@ -1,7 +1,7 @@
{#
/**
* @file
- * Default theme implementation to display a table.
+ * Implementation to display a table.
*
* Available variables:
* - attributes: HTML attributes to apply to the
tag.
diff --git a/core/themes/classy/templates/dataset/tablesort-indicator.html.twig b/core/themes/classy/templates/dataset/tablesort-indicator.html.twig
index 059805f..9d42510 100644
--- a/core/themes/classy/templates/dataset/tablesort-indicator.html.twig
+++ b/core/themes/classy/templates/dataset/tablesort-indicator.html.twig
@@ -1,7 +1,7 @@
{#
/**
* @file
- * Default theme implementation for displaying a tablesort indicator.
+ * Implementation for displaying a tablesort indicator.
*
* Available variables:
* - style: Either 'asc' or 'desc', indicating the sorting direction.
diff --git a/core/themes/classy/templates/field/field--comment.html.twig b/core/themes/classy/templates/field/field--comment.html.twig
index 595bc50..5d93e06 100644
--- a/core/themes/classy/templates/field/field--comment.html.twig
+++ b/core/themes/classy/templates/field/field--comment.html.twig
@@ -1,7 +1,7 @@
{#
/**
* @file
- * Default theme override for comment fields.
+ * Override for comment fields.
*
* Available variables:
* - attributes: HTML attributes for the containing element.
diff --git a/core/themes/classy/templates/field/field--node--created.html.twig b/core/themes/classy/templates/field/field--node--created.html.twig
index 496d6b2..d730342 100644
--- a/core/themes/classy/templates/field/field--node--created.html.twig
+++ b/core/themes/classy/templates/field/field--node--created.html.twig
@@ -1,7 +1,7 @@
{#
/**
* @file
- * Default theme implementation for the node created field.
+ * Implementation for the node created field.
*
* This is an override of field.html.twig for the node created field. See that
* template for documentation about its details and overrides.
diff --git a/core/themes/classy/templates/field/field--node--title.html.twig b/core/themes/classy/templates/field/field--node--title.html.twig
index 5b37bfa..dbbb749 100644
--- a/core/themes/classy/templates/field/field--node--title.html.twig
+++ b/core/themes/classy/templates/field/field--node--title.html.twig
@@ -1,7 +1,7 @@
{#
/**
* @file
- * Default theme implementation for the node title field.
+ * Implementation for the node title field.
*
* This is an override of field.html.twig for the node title field. See that
* template for documentation about its details and overrides.
diff --git a/core/themes/classy/templates/field/field--node--uid.html.twig b/core/themes/classy/templates/field/field--node--uid.html.twig
index 0798d7e..60d0320 100644
--- a/core/themes/classy/templates/field/field--node--uid.html.twig
+++ b/core/themes/classy/templates/field/field--node--uid.html.twig
@@ -1,7 +1,7 @@
{#
/**
* @file
- * Default theme implementation for the node user field.
+ * Implementation for the node user field.
*
* This is an override of field.html.twig for the node user field. See that
* template for documentation about its details and overrides.
diff --git a/core/themes/classy/templates/field/field.html.twig b/core/themes/classy/templates/field/field.html.twig
index 0745f84..f3464ff 100644
--- a/core/themes/classy/templates/field/field.html.twig
+++ b/core/themes/classy/templates/field/field.html.twig
@@ -1,7 +1,7 @@
{#
/**
* @file
- * Default theme implementation for a field.
+ * Implementation for a field.
*
* To override output, copy the "field.html.twig" from the templates directory
* to your theme's directory and customize it, just like customizing other
diff --git a/core/themes/classy/templates/field/file-link.html.twig b/core/themes/classy/templates/field/file-link.html.twig
index fbbf08b..f5be31c 100644
--- a/core/themes/classy/templates/field/file-link.html.twig
+++ b/core/themes/classy/templates/field/file-link.html.twig
@@ -1,7 +1,7 @@
{#
/**
* @file
- * Default theme implementation for a link to a file.
+ * Implementation for a link to a file.
*
* Available variables:
* - attributes: The HTML attributes for the containing element.
diff --git a/core/themes/classy/templates/field/image-formatter.html.twig b/core/themes/classy/templates/field/image-formatter.html.twig
index 0283fcc..7116417 100644
--- a/core/themes/classy/templates/field/image-formatter.html.twig
+++ b/core/themes/classy/templates/field/image-formatter.html.twig
@@ -1,7 +1,7 @@
{#
/**
* @file
- * Default theme implementation to display a formatted image field.
+ * Implementation to display a formatted image field.
*
* Available variables:
* - image: A collection of image data.
diff --git a/core/themes/classy/templates/field/image-style.html.twig b/core/themes/classy/templates/field/image-style.html.twig
index 6d70ade..d1bb940 100644
--- a/core/themes/classy/templates/field/image-style.html.twig
+++ b/core/themes/classy/templates/field/image-style.html.twig
@@ -1,7 +1,7 @@
{#
/**
* @file
- * Default theme implementation for an image using a specific image style.
+ * Implementation for an image using a specific image style.
*
* Available variables:
* - attributes: HTML attributes for the image, including the following:
diff --git a/core/themes/classy/templates/field/image.html.twig b/core/themes/classy/templates/field/image.html.twig
index 2f29304..1f16449 100644
--- a/core/themes/classy/templates/field/image.html.twig
+++ b/core/themes/classy/templates/field/image.html.twig
@@ -1,7 +1,7 @@
{#
/**
* @file
- * Default theme implementation of an image.
+ * Implementation of an image.
*
* Available variables:
* - attributes: HTML attributes for the img tag.
diff --git a/core/themes/classy/templates/field/link-formatter-link-separate.html.twig b/core/themes/classy/templates/field/link-formatter-link-separate.html.twig
index 16b91ed..62da75e 100644
--- a/core/themes/classy/templates/field/link-formatter-link-separate.html.twig
+++ b/core/themes/classy/templates/field/link-formatter-link-separate.html.twig
@@ -1,7 +1,7 @@
{#
/**
* @file
- * Default theme implementation of a link with separate title and URL elements.
+ * Implementation of a link with separate title and URL elements.
*
* Available variables:
* - link: The link that has already been formatted by l().
diff --git a/core/themes/classy/templates/field/time.html.twig b/core/themes/classy/templates/field/time.html.twig
index 521df56..1dbbb98 100644
--- a/core/themes/classy/templates/field/time.html.twig
+++ b/core/themes/classy/templates/field/time.html.twig
@@ -1,7 +1,7 @@
{#
/**
* @file
- * Default theme implementation for a date / time element.
+ * Implementation for a date / time element.
*
* Available variables
* - timestamp: (optional) A UNIX timestamp for the datetime attribute. If the
diff --git a/core/themes/classy/templates/form/checkboxes.html.twig b/core/themes/classy/templates/form/checkboxes.html.twig
index 7c56355..34cd632 100644
--- a/core/themes/classy/templates/form/checkboxes.html.twig
+++ b/core/themes/classy/templates/form/checkboxes.html.twig
@@ -1,7 +1,7 @@
{#
/**
* @file
- * Default theme implementation for a 'checkboxes' #type form element.
+ * Implementation for a 'checkboxes' #type form element.
*
* Available variables
* - attributes: A list of HTML attributes for the wrapper element.
diff --git a/core/themes/classy/templates/form/confirm-form.html.twig b/core/themes/classy/templates/form/confirm-form.html.twig
index d714917..aeff1c0 100644
--- a/core/themes/classy/templates/form/confirm-form.html.twig
+++ b/core/themes/classy/templates/form/confirm-form.html.twig
@@ -1,7 +1,7 @@
{#
/**
* @file
- * Default theme implementation for confirm form.
+ * Implementation for confirm form.
*
* By default this does not alter the appearance of a form at all,
* but is provided as a convenience for themers.
diff --git a/core/themes/classy/templates/form/container.html.twig b/core/themes/classy/templates/form/container.html.twig
index 6fb8159..c49d01d 100644
--- a/core/themes/classy/templates/form/container.html.twig
+++ b/core/themes/classy/templates/form/container.html.twig
@@ -1,7 +1,7 @@
{#
/**
* @file
- * Default theme implementation of a container used to wrap child elements.
+ * Implementation of a container used to wrap child elements.
*
* Used for grouped form items. Can also be used as a #theme_wrapper for any
* renderable element, to surround it with a and HTML attributes.
diff --git a/core/themes/classy/templates/form/datetime-form.html.twig b/core/themes/classy/templates/form/datetime-form.html.twig
index bf31668..51e6a7c 100644
--- a/core/themes/classy/templates/form/datetime-form.html.twig
+++ b/core/themes/classy/templates/form/datetime-form.html.twig
@@ -1,7 +1,7 @@
{#
/**
* @file
- * Default theme implementation of a datetime form element.
+ * Implementation of a datetime form element.
*
* Available variables:
* - attributes: HTML attributes for the datetime form element.
diff --git a/core/themes/classy/templates/form/datetime-wrapper.html.twig b/core/themes/classy/templates/form/datetime-wrapper.html.twig
index 45ba069..e10988a 100644
--- a/core/themes/classy/templates/form/datetime-wrapper.html.twig
+++ b/core/themes/classy/templates/form/datetime-wrapper.html.twig
@@ -1,7 +1,7 @@
{#
/**
* @file
- * Default theme implementation of a datetime form wrapper.
+ * Implementation of a datetime form wrapper.
*
* Available variables:
* - content: The form element to be output, usually a datelist, or datetime.
diff --git a/core/themes/classy/templates/form/details.html.twig b/core/themes/classy/templates/form/details.html.twig
index 17ea820..f79637b 100644
--- a/core/themes/classy/templates/form/details.html.twig
+++ b/core/themes/classy/templates/form/details.html.twig
@@ -1,7 +1,7 @@
{#
/**
* @file
- * Default theme implementation for a details element.
+ * Implementation for a details element.
*
* Available variables
* - attributes: A list of HTML attributes for the details element.
diff --git a/core/themes/classy/templates/form/dropbutton-wrapper.html.twig b/core/themes/classy/templates/form/dropbutton-wrapper.html.twig
index ca0ff7e..82ee836 100644
--- a/core/themes/classy/templates/form/dropbutton-wrapper.html.twig
+++ b/core/themes/classy/templates/form/dropbutton-wrapper.html.twig
@@ -1,7 +1,7 @@
{#
/**
* @file
- * Default theme implementation for a dropbutton wrapper.
+ * Implementation for a dropbutton wrapper.
*
* Available variables:
* - children: Contains the child elements of the dropbutton menu.
diff --git a/core/themes/classy/templates/form/field-multiple-value-form.html.twig b/core/themes/classy/templates/form/field-multiple-value-form.html.twig
index f18a853..5b3fc65 100644
--- a/core/themes/classy/templates/form/field-multiple-value-form.html.twig
+++ b/core/themes/classy/templates/form/field-multiple-value-form.html.twig
@@ -1,7 +1,7 @@
{#
/**
* @file
- * Default theme implementation for an individual form element.
+ * Implementation for an individual form element.
*
* Available variables for all fields:
* - multiple: Whether there are multiple instances of the field.
diff --git a/core/themes/classy/templates/form/fieldset.html.twig b/core/themes/classy/templates/form/fieldset.html.twig
index ab6796c..9cd5547 100644
--- a/core/themes/classy/templates/form/fieldset.html.twig
+++ b/core/themes/classy/templates/form/fieldset.html.twig
@@ -1,7 +1,7 @@
{#
/**
* @file
- * Default theme implementation for a fieldset element and its children.
+ * Implementation for a fieldset element and its children.
*
* Available variables:
* - attributes: HTML attributes for the fieldset element.
diff --git a/core/themes/classy/templates/form/form-element-label.html.twig b/core/themes/classy/templates/form/form-element-label.html.twig
index 6ececd9..5cb8f70 100644
--- a/core/themes/classy/templates/form/form-element-label.html.twig
+++ b/core/themes/classy/templates/form/form-element-label.html.twig
@@ -1,7 +1,7 @@
{#
/**
* @file
- * Default theme implementation for a form element label.
+ * Implementation for a form element label.
*
* Available variables:
* - title: The label's text.
diff --git a/core/themes/classy/templates/form/form-element.html.twig b/core/themes/classy/templates/form/form-element.html.twig
index a961801..d007e4c 100644
--- a/core/themes/classy/templates/form/form-element.html.twig
+++ b/core/themes/classy/templates/form/form-element.html.twig
@@ -1,7 +1,7 @@
{#
/**
* @file
- * Default theme implementation for a form element.
+ * Implementation for a form element.
*
* Available variables:
* - attributes: HTML attributes for the containing element.
diff --git a/core/themes/classy/templates/form/form.html.twig b/core/themes/classy/templates/form/form.html.twig
index 2cd1e95..673ff85 100644
--- a/core/themes/classy/templates/form/form.html.twig
+++ b/core/themes/classy/templates/form/form.html.twig
@@ -1,7 +1,7 @@
{#
/**
* @file
- * Default theme implementation for a 'form' element.
+ * Implementation for a 'form' element.
*
* Available variables
* - attributes: A list of HTML attributes for the wrapper element.
diff --git a/core/themes/classy/templates/form/input.html.twig b/core/themes/classy/templates/form/input.html.twig
index 1409c25..edce771 100644
--- a/core/themes/classy/templates/form/input.html.twig
+++ b/core/themes/classy/templates/form/input.html.twig
@@ -1,7 +1,7 @@
{#
/**
* @file
- * Default theme implementation for an 'input' #type form element.
+ * Implementation for an 'input' #type form element.
*
* Available variables:
* - attributes: A list of HTML attributes for the input element.
diff --git a/core/themes/classy/templates/form/radios.html.twig b/core/themes/classy/templates/form/radios.html.twig
index bf38830..662929a 100644
--- a/core/themes/classy/templates/form/radios.html.twig
+++ b/core/themes/classy/templates/form/radios.html.twig
@@ -1,7 +1,7 @@
{#
/**
* @file
- * Default theme implementation for a 'radios' #type form element.
+ * Implementation for a 'radios' #type form element.
*
* Available variables
* - attributes: A list of HTML attributes for the wrapper element.
diff --git a/core/themes/classy/templates/form/select.html.twig b/core/themes/classy/templates/form/select.html.twig
index 21f32ac..7e417ac 100644
--- a/core/themes/classy/templates/form/select.html.twig
+++ b/core/themes/classy/templates/form/select.html.twig
@@ -1,7 +1,7 @@
{#
/**
* @file
- * Default theme implementation for a select element.
+ * Implementation for a select element.
*
* Available variables:
* - attributes: HTML attributes for the select tag.
diff --git a/core/themes/classy/templates/form/textarea.html.twig b/core/themes/classy/templates/form/textarea.html.twig
index 8a8426d..d6a43cc 100644
--- a/core/themes/classy/templates/form/textarea.html.twig
+++ b/core/themes/classy/templates/form/textarea.html.twig
@@ -1,7 +1,7 @@
{#
/**
* @file
- * Default theme implementation for a 'textarea' #type form element.
+ * Implementation for a 'textarea' #type form element.
*
* Available variables
* - wrapper_attributes: A list of HTML attributes for the wrapper element.
diff --git a/core/themes/classy/templates/layout/book-export-html.html.twig b/core/themes/classy/templates/layout/book-export-html.html.twig
index cbeb3b3..e40ec58 100644
--- a/core/themes/classy/templates/layout/book-export-html.html.twig
+++ b/core/themes/classy/templates/layout/book-export-html.html.twig
@@ -1,7 +1,7 @@
{#
/**
* @file
- * Default theme implementation for printed version of book outline.
+ * Implementation for printed version of book outline.
*
* Available variables:
* - title: Top level node title.
diff --git a/core/themes/classy/templates/layout/html.html.twig b/core/themes/classy/templates/layout/html.html.twig
index 888cf2d..43aec4d 100644
--- a/core/themes/classy/templates/layout/html.html.twig
+++ b/core/themes/classy/templates/layout/html.html.twig
@@ -1,7 +1,7 @@
{#
/**
* @file
- * Default theme implementation for the basic structure of a single Drupal page.
+ * Implementation for the basic structure of a single Drupal page.
*
* Variables:
* - logged_in: A flag indicating if user is logged in.
diff --git a/core/themes/classy/templates/layout/maintenance-page.html.twig b/core/themes/classy/templates/layout/maintenance-page.html.twig
index eaae5ab..d158fc8 100644
--- a/core/themes/classy/templates/layout/maintenance-page.html.twig
+++ b/core/themes/classy/templates/layout/maintenance-page.html.twig
@@ -1,7 +1,7 @@
{#
/**
* @file
- * Default theme implementation to display a single Drupal page while offline.
+ * Implementation to display a single Drupal page while offline.
*
* All available variables are mirrored in page.html.twig.
* Some may be blank but they are provided for consistency.
diff --git a/core/themes/classy/templates/layout/page.html.twig b/core/themes/classy/templates/layout/page.html.twig
index 437a11c..821ae9c 100644
--- a/core/themes/classy/templates/layout/page.html.twig
+++ b/core/themes/classy/templates/layout/page.html.twig
@@ -1,7 +1,7 @@
{#
/**
* @file
- * Default theme implementation to display a single page.
+ * Implementation to display a single page.
*
* The doctype, html, head and body tags are not in this template. Instead they
* can be found in the html.html.twig template in this directory.
diff --git a/core/themes/classy/templates/layout/region.html.twig b/core/themes/classy/templates/layout/region.html.twig
index b2c5471..97a82dd 100644
--- a/core/themes/classy/templates/layout/region.html.twig
+++ b/core/themes/classy/templates/layout/region.html.twig
@@ -1,7 +1,7 @@
{#
/**
* @file
- * Default theme implementation to display a region.
+ * Implementation to display a region.
*
* Available variables:
* - content: The content for this region, typically blocks.
diff --git a/core/themes/classy/templates/misc/feed-icon.html.twig b/core/themes/classy/templates/misc/feed-icon.html.twig
index b3c10d1..5cc5017 100644
--- a/core/themes/classy/templates/misc/feed-icon.html.twig
+++ b/core/themes/classy/templates/misc/feed-icon.html.twig
@@ -1,7 +1,7 @@
{#
/**
* @file
- * Default theme implementation for a feed icon.
+ * Implementation for a feed icon.
*
* Available variables:
* - url: An internal system path or a fully qualified external URL of the feed.
diff --git a/core/themes/classy/templates/misc/progress-bar.html.twig b/core/themes/classy/templates/misc/progress-bar.html.twig
index 885a80f..f0aef16 100644
--- a/core/themes/classy/templates/misc/progress-bar.html.twig
+++ b/core/themes/classy/templates/misc/progress-bar.html.twig
@@ -1,7 +1,7 @@
{#
/**
* @file
- * Default theme implementation for a progress bar.
+ * Implementation for a progress bar.
*
* Note that the core Batch API uses this only for non-JavaScript batch jobs.
*
diff --git a/core/themes/classy/templates/misc/rdf-metadata.html.twig b/core/themes/classy/templates/misc/rdf-metadata.html.twig
index 4f65294..c243c17 100644
--- a/core/themes/classy/templates/misc/rdf-metadata.html.twig
+++ b/core/themes/classy/templates/misc/rdf-metadata.html.twig
@@ -1,7 +1,7 @@
{#
/**
* @file
- * Default theme implementation for empty spans with RDF attributes.
+ * Implementation for empty spans with RDF attributes.
*
* The XHTML+RDFa doctype allows either or syntax to
* be used, but for maximum browser compatibility, W3C recommends the
diff --git a/core/themes/classy/templates/misc/status-messages.html.twig b/core/themes/classy/templates/misc/status-messages.html.twig
index fb1ebe3..9004c1c 100644
--- a/core/themes/classy/templates/misc/status-messages.html.twig
+++ b/core/themes/classy/templates/misc/status-messages.html.twig
@@ -1,7 +1,7 @@
{#
/**
* @file
- * Default theme implementation for status messages.
+ * Implementation for status messages.
*
* Displays status, error, and warning messages, grouped by type.
*
diff --git a/core/themes/classy/templates/navigation/book-all-books-block.html.twig b/core/themes/classy/templates/navigation/book-all-books-block.html.twig
index 6160982..05d3612 100644
--- a/core/themes/classy/templates/navigation/book-all-books-block.html.twig
+++ b/core/themes/classy/templates/navigation/book-all-books-block.html.twig
@@ -1,7 +1,7 @@
{#
/**
* @file
- * Default theme implementation for rendering book outlines within a block.
+ * Implementation for rendering book outlines within a block.
*
* This template is used only when the block is configured to "show block on all
* pages", which presents multiple independent books on all pages.
diff --git a/core/themes/classy/templates/navigation/book-navigation.html.twig b/core/themes/classy/templates/navigation/book-navigation.html.twig
index abb0d31..a65d434 100644
--- a/core/themes/classy/templates/navigation/book-navigation.html.twig
+++ b/core/themes/classy/templates/navigation/book-navigation.html.twig
@@ -1,7 +1,7 @@
{#
/**
* @file
- * Default theme implementation to navigate books.
+ * Implementation to navigate books.
*
* Presented under nodes that are a part of book outlines.
*
diff --git a/core/themes/classy/templates/navigation/book-tree.html.twig b/core/themes/classy/templates/navigation/book-tree.html.twig
index 9f640d0..f38ee27 100644
--- a/core/themes/classy/templates/navigation/book-tree.html.twig
+++ b/core/themes/classy/templates/navigation/book-tree.html.twig
@@ -1,7 +1,7 @@
{#
/**
* @file
- * Default theme implementation for a book tree.
+ * Implementation for a book tree.
*
* Returns HTML for a wrapper for a book sub-tree.
*
diff --git a/core/themes/classy/templates/navigation/breadcrumb.html.twig b/core/themes/classy/templates/navigation/breadcrumb.html.twig
index f6a1705..1165aaf 100644
--- a/core/themes/classy/templates/navigation/breadcrumb.html.twig
+++ b/core/themes/classy/templates/navigation/breadcrumb.html.twig
@@ -1,7 +1,7 @@
{#
/**
* @file
- * Default theme implementation for a breadcrumb trail.
+ * Implementation for a breadcrumb trail.
*
* Available variables:
* - breadcrumb: Breadcrumb trail items.
diff --git a/core/themes/classy/templates/navigation/links.html.twig b/core/themes/classy/templates/navigation/links.html.twig
index 56c7ec2..936d729 100644
--- a/core/themes/classy/templates/navigation/links.html.twig
+++ b/core/themes/classy/templates/navigation/links.html.twig
@@ -1,7 +1,7 @@
{#
/**
* @file
- * Default theme implementation for a set of links.
+ * Implementation for a set of links.
*
* Available variables:
* - attributes: Attributes for the UL containing the list of links.
diff --git a/core/themes/classy/templates/navigation/menu-local-action.html.twig b/core/themes/classy/templates/navigation/menu-local-action.html.twig
index 0eb03a9..4607dad 100644
--- a/core/themes/classy/templates/navigation/menu-local-action.html.twig
+++ b/core/themes/classy/templates/navigation/menu-local-action.html.twig
@@ -1,7 +1,7 @@
{#
/**
* @file
- * Default theme implementation for a single local action link.
+ * Implementation for a single local action link.
*
* Available variables:
* - attributes: HTML attributes for the wrapper element.
diff --git a/core/themes/classy/templates/navigation/menu-local-task.html.twig b/core/themes/classy/templates/navigation/menu-local-task.html.twig
index 5939203..4796144 100644
--- a/core/themes/classy/templates/navigation/menu-local-task.html.twig
+++ b/core/themes/classy/templates/navigation/menu-local-task.html.twig
@@ -1,7 +1,7 @@
{#
/**
* @file
- * Default theme implementation for a local task link.
+ * Implementation for a local task link.
*
* Available variables:
* - attributes: HTML attributes for the wrapper element.
diff --git a/core/themes/classy/templates/navigation/menu-local-tasks.html.twig b/core/themes/classy/templates/navigation/menu-local-tasks.html.twig
index dce922b..d80c144 100644
--- a/core/themes/classy/templates/navigation/menu-local-tasks.html.twig
+++ b/core/themes/classy/templates/navigation/menu-local-tasks.html.twig
@@ -1,7 +1,7 @@
{#
/**
* @file
- * Default theme implementation to display primary and secondary local tasks.
+ * Implementation to display primary and secondary local tasks.
*
* Available variables:
* - primary: HTML list items representing primary tasks.
diff --git a/core/themes/classy/templates/navigation/menu.html.twig b/core/themes/classy/templates/navigation/menu.html.twig
index f01ce84..ea61e90 100644
--- a/core/themes/classy/templates/navigation/menu.html.twig
+++ b/core/themes/classy/templates/navigation/menu.html.twig
@@ -1,7 +1,7 @@
{#
/**
* @file
- * Default theme implementation to display a menu.
+ * Implementation to display a menu.
*
* Available variables:
* - menu_name: The machine name of the menu.
diff --git a/core/themes/classy/templates/navigation/pager.html.twig b/core/themes/classy/templates/navigation/pager.html.twig
index a7acd5e..0fcc201 100644
--- a/core/themes/classy/templates/navigation/pager.html.twig
+++ b/core/themes/classy/templates/navigation/pager.html.twig
@@ -1,7 +1,7 @@
{#
/**
* @file
- * Default theme implementation to display a pager.
+ * Implementation to display a pager.
*
* Available variables:
* - items: List of pager items.
diff --git a/core/themes/classy/templates/navigation/toolbar.html.twig b/core/themes/classy/templates/navigation/toolbar.html.twig
index 5d2737d..e83b744 100644
--- a/core/themes/classy/templates/navigation/toolbar.html.twig
+++ b/core/themes/classy/templates/navigation/toolbar.html.twig
@@ -1,7 +1,7 @@
{#
/**
* @file
- * Default theme implementation for the administrative toolbar.
+ * Implementation for the administrative toolbar.
*
* Available variables:
* - attributes: HTML attributes for the wrapper.
diff --git a/core/themes/classy/templates/navigation/vertical-tabs.html.twig b/core/themes/classy/templates/navigation/vertical-tabs.html.twig
index 5b7298b..69d0527 100644
--- a/core/themes/classy/templates/navigation/vertical-tabs.html.twig
+++ b/core/themes/classy/templates/navigation/vertical-tabs.html.twig
@@ -1,7 +1,7 @@
{#
/**
* @file
- * Default theme implementation for vertical tabs.
+ * Implementation for vertical tabs.
*
* Available variables
* - attributes: A list of HTML attributes for the wrapper element.
diff --git a/core/themes/classy/templates/user/forum-submitted.html.twig b/core/themes/classy/templates/user/forum-submitted.html.twig
index 8d36a51..eee54d2 100644
--- a/core/themes/classy/templates/user/forum-submitted.html.twig
+++ b/core/themes/classy/templates/user/forum-submitted.html.twig
@@ -1,7 +1,7 @@
{#
/**
* @file
- * Default theme implementation for a forum post submission string.
+ * Implementation for a forum post submission string.
*
* The submission string indicates when and by whom a topic was submitted.
*
diff --git a/core/themes/classy/templates/user/user.html.twig b/core/themes/classy/templates/user/user.html.twig
index c44448b..54648a9 100644
--- a/core/themes/classy/templates/user/user.html.twig
+++ b/core/themes/classy/templates/user/user.html.twig
@@ -1,7 +1,7 @@
{#
/**
* @file
- * Default theme implementation to present all user data.
+ * Implementation to present all user data.
*
* This template is used when viewing a registered user's page,
* e.g., example.com/user/123. 123 being the user's ID.
diff --git a/core/themes/classy/templates/user/username.html.twig b/core/themes/classy/templates/user/username.html.twig
index 7859376..9d8143d 100644
--- a/core/themes/classy/templates/user/username.html.twig
+++ b/core/themes/classy/templates/user/username.html.twig
@@ -1,7 +1,7 @@
{#
/**
* @file
- * Default theme implementation for displaying a username.
+ * Implementation for displaying a username.
*
* Available variables:
* - account: The full account information for the user.