Set Target Namespace
The Set Target Namespace command enables a target namespace to be set for a taxonomy document. Clicking the command pops up the Set Target Namespace dialog (screenshot below). In it you can enter the desired target namespace and a prefix for it. Click OK to finish.
The target namespace will be defined and it will also be declared:
<xs:schema targetNamespace="https://www.altova.com/XBRL/Taxonomies"
xmlns:ns1="https://www.altova.com/XBRL/Taxonomies" >
...
</xs:schema>
In the listing above, the target namespace is defined with the targetNamespace attribute and it is then declared with a prefix of ns1.