If direct and indirect/non-direct objects are distinguished in their coding, then they also differ in their syntactic behaviour (but not necessarily the reverse).
Standardized
IF direct and indirect/non-direct objects are distinguished in their coding, THEN they also differ in their syntactic behavior (but not necessarily the reverse).
Keywords
grammatical relations, object, indirect, non-direct, direct
## 953,955, and 956 seem to me identical. Why list them three times!?