The block is handling its own caching in its hook_block_view().

This setting is useful when time based expiration is needed or a site uses a node access which invalidates standard block cache.

Related topics

Block Caching Constants that define each block's caching state.

File

core/includes/common.inc, line 139
Common functions that many Backdrop modules will need to reference.

Code

define('BACKDROP_CACHE_CUSTOM', -2)