What is the 'n' variable in the invocation tag?

The 'n' variable is a random string generated for naming cookies. You'll notice that each time you hit 'generate' on the invocation tag page, the 'n' value will be different even for the same zone.

Every invocation tag on a single page should have a unique 'n' value as the cookies contain information for the banner that was displayed. It ensures that if the user clicks on the banner they are redirected to the correct destination. The 'n' value should be the same within a single invocation tag - so for an IMG tag, the link href and img src should both use the same 'n' value.

If you are wanting to generate invocation tags yourself, there are no strict requirements on the value of the variable. It is generated as an 8 character alphanumeric value - special characters should be avoided because of possible encoding issues.