... Possible
1
Required for DEPEND_i and LABEL_i if record-varying
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
... Required
2
Not required if LABEL_i is present
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
... Required
3
Not required if DEPEND_i is present
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .