DDEX messages make use of two-letter ISO territory codes. This allows a label to state that a Release may be used in, say the “DACH” countries:
<TerritoryCode>DE</TerritoryCode> <TerritoryCode>AT</TerritoryCode> <TerritoryCode>CH</TerritoryCode>
It also allows to say that a deal is available everywhere but in the DACH countries:
<ExcludedTerritoryCode>DE</ExcludedTerritoryCode> <ExcludedTerritoryCode>AT</ExcludedTerritoryCode> <ExcludedTerritoryCode>CH</ExcludedTerritoryCode>
The latter XML snipped has the semantic of "World-wide, less Germany, Austria, Switzerland". .
To avoid this pitfall, the label should limit its Deals to the territories it would want the DSP to make the Release available in.
DSP expanding its territorial reach
If a label sends a DSP, who operates in only one territory a Deal with
<TerritoryCode> Worldwide </TerritoryCode>
and the DSP subsequently choses to branch out its operation into a second territory, the Deal would allow the DSP to make the relevant Release available in both territories.
For a list of valid ISO Territory Codes please refer to Wikipedia for details.