This attribute allows to replace the content of a note with the content of a variable.
Suppose to have a variable
foo with a value
My name is John and the following template:
<div id="pagination" t:content="foo"> This <b>content</b> will be removed </div>
The output will be:
<div id="pagination">My name is John</div>
This can be useful to put come “test” content in your templates that will have a nice aspect on WYSIWYG editors, but at runtime will be replaced by real data coming from variables.