8.4.18 EqCAliphaticONS

Oxygen nitrogen sulfur equivalence flag. When set, query atoms which are oxygen, nitrogen, or sulfur based on the return value of the OEAtomBase::GetAtomicNum method and are not aromatic based on the return value of the OEAtomBase::IsAromatic method are equivalent to a potential match atom which is also either oxygen, nitrogen, or sulfur and not aromatic.