An OmniGroup is simply a node that wraps other OmniElements that are logically similar to promote readability. In the following example, the Military OmniGroup logically groups several like fields together:
<Person >
<SourceName>TestSystem</SourceName>
<SourceInstanceId>Patient:12345678:Person:PersonKey</SourceInstanceId>
<Military>
<VeteranStatus sourceCode="Reserves"
sourceCodeSet="VeteranStatusCodes">Reserves </VeteranStatus>
<Branch sourceCode="Army" sourceCodeSet="MilitaryBranchCodes">United
States Army</Branch>
<Category sourceCode="A14"
sourceCodeSet="MilitaryCategoryCodes">A14</Category>
<Component sourceCode="AR"
sourceCodeSet="MilitaryComponentCodes">Army</Component>
<PayGrade>E-7</PayGrade>
<Rank sourceCode="E7" sourceCodeSet="MilitaryRankCodes">Enlisted
Level 7</Rank>
<UnitId>platoon</UnitId>
</Military>
</Person >