By tim.plunkett on
Change record status: 
Published (View all published change records)
Project: 
Drupal core
Introduced in branch: 
8.3.x
Introduced in version: 
8.3.0
Issue links: 
https://www.drupal.org/node/2829680
Description: 

The BLOCK_LABEL_VISIBLE constant contains a magic string used for the "label display" setting of blocks.
After BlockInterface and BlockPluginInterface were split, the constant was added to the wrong interface.

It is now \Drupal\Core\Block\BlockPluginInterface::BLOCK_LABEL_VISIBLE and the old constant is deprecated.

Impacts: 
Module developers