Using the only Attribute to Limit the Namespace

The only attribute, unique to the dtml-with tag, prunes the enclosing namespaces when rendering the body of the tag. This is advantageous to prevent acquisition within DTML:

<dtml-with REQUEST only>
<dtml-unless id>
An id was not specified.

<dtml-/unless>

<dtml-/with>

Without the only attribute, the above DTML would likely get an id value from the enclosing environment, which, in this example, is unwanted.