When you build expressions with <template> that use XML delimiters natively in the expression, you need to double-escape XML delimiters. This is required because <template> expressions are evaluated twice to fully resolve expressions.

A common example is building URLs with <template> to use in <directinvoke>. URLs that contain query parameters use the & character to separate the parameter/value pairs. In this case, you need to escape the & character twice to avoid syntax errors. For example:

The first evaluation resolves &amp;amp; to &amp; which is then properly resolved in the second evaluation when the mashup script is run to &.