There are several issues in core about making the use of the \ in namespaces consistent in core. Some of the work in those issues overlaps each other.
#3144809: PHPCS rule for consistent usage of '\Drupal' →
#2859992: [PP-1] Consistent use of leading \ for class names in *.api.php files →
#2912687: [PP-1] Consistent use of leading \ for class names in comments →
#3082854: [PP-1] Consistently use \Drupal::foo() instead of Drupal::foo() →
#3089634: missing initial backslash on parameter interface typehints in entity.api.php →
#3123593: [PP-1] Class names in *.services.yml inconsistently use leading \ →
Create a meta to separate the work into clearly defined manageable pieces. Mark all as postponed on #3054969: Add sniff for \Drupal vs Drupal → .
Postponed
11.0 🔥
other
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