Plugins may want to contribute additional restrictions on the use of specific labels for specific projects. This extension point allows such restrictions.
... Link 29: 23265 1488960 java.net.URL 30: 42664 1365248 java.util.concurrent.locks.ReentrantLock$NonfairSync 31: 85219 1363504 com.cloudbees.groovy.cps.impl ...
Missing: extensible- choice- use/