The DDWKEY0013 message is a warning that a key contains signed numeric fields. It just tells you that a field that makes up a key is signed numeric.
This is normal for the DDD-DATABASE and can be ignored.
The same warnings may have been seen with prior releases of CA Datacom as well.
From the DDWKEY0013 message description on DocOps:
DDWKEY0013: SIGNED NUMERIC FIELD IN KEY
During the verification of a DATABASE structure, a KEY substructure was detected that contains a FIELD entity-occurrence with a TYPE attribute-value of N or D and a SIGN attribute-value of Y. Use of a signed numeric FIELD entity-occurrence in a key can cause the data records to be sorted and retrieved in a different sequence than expected.
This is a warning message only. No action is required if this manner of sorting and retrieval is acceptable. To obtain a logical sorting sequence, change the KEY entity-occurrence DATA-SENSITIVE attribute-value to Y.