The COPYIN clause specifies that the data in the master thread of the team is to be copied to the thread private copies of the common block at the beginning of the parallel region. It takes the following form:
The COPYIN clause applies only to common blocks declared as THREADPRIVATE (or TASKCOMMON).
You do not need to specify the whole THREADPRIVATE (or TASKCOMMON) common block, you can specify named variables within the common block.