Note: this list is generated by looking for the string for this theme hook, so it may include some references that are not actually using this theme hook.

backdrop_add_html_head in core/includes/
Adds output to the HEAD tag of the HTML page.
backdrop_common_theme in core/includes/
Provides theme registration for themes across .inc files.
backdrop_get_html_head in core/includes/
Retrieves output to be displayed in the HEAD tag of the HTML page.
backdrop_pre_render_scripts in core/includes/
#pre_render callback to add the elements needed for JavaScript tags to be rendered.
backdrop_pre_render_styles in core/includes/
Pre-render callback: Adds the elements needed for CSS tags to be rendered.
field_example_field_formatter_view in modules/examples/field_example/field_example.module
Implements hook_field_formatter_view().
field_permission_example_field_formatter_view in modules/examples/field_permission_example/field_permission_example.module
Implements hook_field_formatter_view().
RenderElementTypesTestCase::testHeadTag in core/modules/simpletest/tests/theme.test
Tests system #type 'head_tag'.
system_element_info in core/modules/system/system.module
Implements hook_element_info().
_backdrop_default_html_head in core/includes/
Returns elements that are always displayed in the HEAD tag of the HTML page.