Adds input box to attached posts to label relationship and saves to a new metakey.
To use give options array show_relation => true
The original meta data isnt touched but an additional meta key is set with the same name + _relation that stores the post id as the key and input value as the value
Adds input box to attached posts to label relationship and saves to a new metakey. To use give options array show_relation => true
The original meta data isnt touched but an additional meta key is set with the same name + _relation that stores the post id as the key and input value as the value